The witness also said her family had been forced to move to Spain to escape her daughter's alleged abusers.
Sheffield Crown Court also heard how police lost tapes of an interview with defendant Sageer Hussain in 2003.
Eight men, including Mr Hussain, deny sexually abusing three girls between 1999 and 2003.
The mother of one of the alleged victims said in a statement: "Her character changed from a lovely girl to an animal. She became horrible."
She said at one stage she discovered a mobile phone in her daughter's bedroom and rang a number stored under the name 'Waleed'.
She said a man picked up the phone and said "I ain't done owt, I ain't touched her. It isn't me".
When she asked her daughter about the phone she said she burst into tears and said "They're raping me, they're raping me".
She told the court after her daughter went to the police in 2003 her family were repeatedly threatened.
"We were so distraught that we sold the business and the home and moved to Spain," she said.
Det Con Andy Stephanek, of South Yorkshire Police, told the court the force had lost the tape of an interview with Mr Hussain when he was first questioned about the allegations.
He said it appeared that "due to the passage of time they've been destroyed".
The trial continues.

The SNP's John Wallace won the Ayr East ward after the vote on Thursday.
Turnout for the by-election was 34.4%, with 4,006 votes cast out of an electorate of 11,638.
The by-election was called following the resignation of Corri Wilson, who was elected as SNP MP for Ayr, Carrick and Cumnock earlier this year.

The 28-year-old was arrested following an investigation by the Queensland Crime and Corruption Commission (CCC).
Two other men and a woman were also charged with supplying cocaine for "personal use or to on-supply cocaine to friends and colleagues".
Hunt has played elite-level rugby league, Australian rules football (AFL) and rugby union.
Hunt - who is due to appear in Southport Magistrate Court on 5 March - was not named by the CCC but local media have named him as the 28-year old man arrested.
He was arrested on Thursday night, just days after playing for the Queensland Reds rugby team.
"The CCC will allege that during an investigation focused on a cocaine trafficking syndicate operating in South East Queensland, these four individuals were identified contacting the syndicate and arranging for the supply of cocaine," a statement said.
It is alleged the offences occurred between June and December 2014 when Hunt was playing AFL for the Gold Coast Suns.
Hunt rose to prominence playing fullback for the Brisbane Broncos rugby league team in 2004, and was selected for Queensland State of Origin and Australian representative squads.
He made a code-switch to AFL with the Gold Coast Suns in 2009.
Hunt played with the team until 2014 when he made a switch to rugby union.
Facing charges with Hunt are a 24-year-old man from Burleigh Waters, a 27-year-old man from Mermaid Waters and a 22-year-old woman from Mermaid Waters.

Janet Jordon, 48, her daughter Derrin, aged six, and her partner Philip Howard, 44, were found in a house in Vicarage Road, Didcot, on 23 May.
The body of murder suspect, Janet's son 21-year-old Jed Allen, was found two days later in woodland near Marston Ferry Road, Oxford.
The private funeral is being held at Oxford Crematorium.
The families of the murder victims described their deaths as an "unimaginable" tragedy.
Post-mortem examinations confirmed all three died from multiple stab wounds.
A woman who was allegedly raped and abused by eight men in Rotherham changed from a "lovely girl to an animal", her mother told jurors.
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The SNP has held a South Ayrshire Council ward following a by-election which was called after the previous incumbent was elected as an MP.
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Australian rugby union star Karmichael Hunt has been charged with supplying cocaine, officials say.
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A funeral is being held for a family who were found stabbed at their home in Didcot, Oxfordshire.