By . Ted Thornhill for MailOnline . A description of John Kerry by Isis as an ‘uncircumcised old geezer’ is further evidence of British involvement in the militant organisation, a terrorism expert has said. The comment about the U.S Secretary of State came in an audio recording by Isis spokesman Abu Mohammad al-Adnani. He said: 'The uncircumcised old . geezer, suddenly became an Islamic jurist, issuing a verdict to the . people that the Islamic State was distorting Islam, that what it was . doing was against Islamic teachings, and that the Islamic State was an . enemy of Islam.' Connection: The use of the word 'geezer' in the translation of al-Adnani's description of John Kerry is yet more evidence of strong ties between Britain and Isis, according to an expert . Professor Anthony Glees, head of the . centre for security and intelligence studies at the University of . Buckingham, said the use of British slang was hugely significant. He told MailOnline: ‘I'd say the use of . the word "geezer" is a massively important further giveaway about the . identity of some of these Isis thugs. It's a term most usually heard in . London. 'So Isis have drawn us, I'd suspect intentionally, back towards reflecting on the fact that Brits are fighting for these sadistic butchers, taunting not just the families of the hostages but our government and our position in the world.' His comments came as experts revealed that the terrorist group is using its control of oil fields to fund its brutal operations. Britain's link to Islamic State became known around the world after shocking videos showed a British man known as 'Jihadi John' executing American journalists James Foley, 40, and Steven Sotloff, 31, as well as British aid worker David Haines, 44. Some sources believe that Jihadi John comes from a South London suburb about 10 miles from Central London. Professor Glees added: 'It's my understanding that MI5 and the counter-terrorism police do know the identity of "John" but that like the UK government more generally they don't see any advantage at this stage in telling the rest of us, not so much out of consideration to "John's" family but to the hostages because this is about the lives of innocent hostages here, and every move that we take needs to be very carefully considered before we take it.' Low blow: The group called John Kerry an 'uncircumcised old geezer' after his comments that the terrorist organization 'did not represent Islam' in front of the House Foreign Affairs Committee . It was made as a fuller picture emerged of Isis's vast wealth - estimated to be around $1.5billion - and slick operation. One Syrian told the Financial Times that he had a job interview with Isis to work in its media centre in Raqqa, Syria's capital, and that he was amazed at the salary he was offered and the equipment he would have at his disposal. The man, who turned the job down, said: 'They offered me $1,500 a month [five times the average Syrian salary], plus a car, a house and all the cameras I needed. I remembered looking around the office. It was amazing the equipment they had in there.' The U.S is becoming increasingly focussed on finding out precisely where the group's money is coming from. Barack Obama and other leaders will discuss the issue at next week's annual United Nations General Assembly. And a new U.S-based research group called the Counter Extremism Project is poised to release to governments and media outlets a database of information about militants and their supporters. It's convinced that Isis is generating a great deal of wealth from shady deals with morally compromised companies. Risk management group Maplecroft believes that Isis controls half a dozen oil fields in Syria and four in Iraq, with many officials convinced it's making millions from smuggling barrels to Turkey, Iran and Iraq. The group is also known to make money from kidnappings, extortion and robbery. More airstrikes are expected this week against the group, and U.S. Ambassador to the United Nations Samantha Power said on Face The Nation Sunday morning that other countries were willing to join the U.S. in these strikes, though she would not say what countries. These strikes have already begun in Iraq, and been authorized to begin in Syria by Obama. In addition, the Senate approved a bill to train and arm moderate Syrian rebels to battle Islamic State militants.
Isis called John Kerry an 'uncircumcised geezer' in an audio recording .
Geezer is known as a British slang word, often spoken in London .
'The use of the word is a giveaway about the identity of these thugs' - expert .
Links between Britain and Isis first emerged through beheading videos .
Jihadi John, thought to be from London, has executed three hostages .
It comes as a fuller picture of Isis's enormous wealth is revealed .
Some experts believe the group is partly funded through oil smuggling .
By . Ted Thornhill for MailOnline . A description of John Kerry by Isis as an ‘uncircumcised old geezer’ is further evidence of British involvement in the militant organisation, a terrorism expert has said. The comment about the U.S Secretary of State came in an audio recording by Isis spokesman Abu Mohammad al-Adnani. He said: 'The uncircumcised old . geezer, suddenly became an Islamic jurist, issuing a verdict to the . people that the Islamic State was distorting Islam, that what it was . doing was against Islamic teachings, and that the Islamic State was an . enemy of Islam.' Connection: The use of the word 'geezer' in the translation of al-Adnani's description of John Kerry is yet more evidence of strong ties between Britain and Isis, according to an expert . Professor Anthony Glees, head of the . centre for security and intelligence studies at the University of . Buckingham, said the use of British slang was hugely significant. He told MailOnline: ‘I'd say the use of . the word "geezer" is a massively important further giveaway about the . identity of some of these Isis thugs. It's a term most usually heard in . London. 'So Isis have drawn us, I'd suspect intentionally, back towards reflecting on the fact that Brits are fighting for these sadistic butchers, taunting not just the families of the hostages but our government and our position in the world.' His comments came as experts revealed that the terrorist group is using its control of oil fields to fund its brutal operations. Britain's link to Islamic State became known around the world after shocking videos showed a British man known as 'Jihadi John' executing American journalists James Foley, 40, and Steven Sotloff, 31, as well as British aid worker David Haines, 44. Some sources believe that Jihadi John comes from a South London suburb about 10 miles from Central London. Professor Glees added: 'It's my understanding that MI5 and the counter-terrorism police do know the identity of "John" but that like the UK government more generally they don't see any advantage at this stage in telling the rest of us, not so much out of consideration to "John's" family but to the hostages because this is about the lives of innocent hostages here, and every move that we take needs to be very carefully considered before we take it.' Low blow: The group called John Kerry an 'uncircumcised old geezer' after his comments that the terrorist organization 'did not represent Islam' in front of the House Foreign Affairs Committee . It was made as a fuller picture emerged of Isis's vast wealth - estimated to be around $1.5billion - and slick operation. One Syrian told the Financial Times that he had a job interview with Isis to work in its media centre in Raqqa, Syria's capital, and that he was amazed at the salary he was offered and the equipment he would have at his disposal. The man, who turned the job down, said: 'They offered me $1,500 a month [five times the average Syrian salary], plus a car, a house and all the cameras I needed. I remembered looking around the office. It was amazing the equipment they had in there.' The U.S is becoming increasingly focussed on finding out precisely where the group's money is coming from. Barack Obama and other leaders will discuss the issue at next week's annual United Nations General Assembly. And a new U.S-based research group called the Counter Extremism Project is poised to release to governments and media outlets a database of information about militants and their supporters. It's convinced that Isis is generating a great deal of wealth from shady deals with morally compromised companies. Risk management group Maplecroft believes that Isis controls half a dozen oil fields in Syria and four in Iraq, with many officials convinced it's making millions from smuggling barrels to Turkey, Iran and Iraq. The group is also known to make money from kidnappings, extortion and robbery. More airstrikes are expected this week against the group, and U.S. Ambassador to the United Nations Samantha Power said on Face The Nation Sunday morning that other countries were willing to join the U.S. in these strikes, though she would not say what countries. These strikes have already begun in Iraq, and been authorized to begin in Syria by Obama. In addition, the Senate approved a bill to train and arm moderate Syrian rebels to battle Islamic State militants.
of John Kerry by Isis as an ‘uncircumcised old U.S Secretary of State came in an audio recording evidence of strong ties between Britain and Isis, Buckingham, said the use of British slang was the use of . the word "geezer" is a massively important further giveaway about the . identity of some of these Isis thugs. It's a term most as experts revealed that the terrorist group is shocking videos showed a British man known as sources believe that Jihadi John comes from a blow: The group called John Kerry an Affairs Committee . It was made as a fuller picture emerged of Isis's vast wealth - estimated to be around $1.5billion - and slick operation.