MOSCOW (Reuters) - Former Russian economy minister Alexei Ulyukayev, accused of extorting a bribe, told a court on Monday he thought a bag holding $2 million in cash which he took from Rosneft (ROSN.MM) chief executive Igor Sechin held a gift of expensive alcohol. Ulyukayev faces up to 15 years in prison if found guilty of  accepting the $2 million cash from Sechin, a close ally of President Vladimir Putin. Prosecutors said the bribe was given last year on Nov. 14 in exchange for Ulyukayev approving the sale of a state-controlled oil company Bashneft (BANE.MM) to Rosneft. Police detained Ulyukayev inside Rosneft headquarters shortly after Sechin handed him the cash inside a lockable brown bag and  a little basket with sausage  as a gift, prosecutors said. . The next day Putin fired Ulyukayev. Ulyukayev, speaking to the court, said he had believed the package contained a gift but that a trap had been set for him.  All this was an action directed against me, planned in advance, a provocation organized in advance,  he said.  Ulyukayev s lawyers are trying to explain to the court why he accepted the bag from Sechin given that - according to transcripts of their conversations - neither man had discussed what was inside. Ulyukayev said when he had been economy minister, Sechin had visited his ministry two or three times and usually had come to the office  with a bulky bag,  containing presents. During that period, Sechin personally presented Ulyukayev with a watch and a model of an  oil-derrick, and he sent a food hamper on occasions such as birthdays, Ulyukayev said. Ulyukayev had also received alcoholic drinks from Sechin as gifts, a prosecutor said.  That was a norm of etiquette,  from Sechin s point of view, Ulyukayev told the court. The ex-minister said the bag which Sechin gave him last year at Rosneft headquarters in a law enforcement sting operation weighed about 15 kg (33 lbs) and he thought there had been expensive wine or spirits inside. Ulyukayev said that a month before, Sechin promised to present him with a wine he  had never tried before in his life  to mark the successful closing of the Bashneft privatization deal. For that reason it came as a surprise that the bag contained money, Ulyukayev said. Sechin has been issued with four summonses to testify in the trial, but has failed to show up, despite being a key witness. His lawyer said in a letter to the court that Sechin had been away on business trips. 