Bruno Wilson on Wednesday gave evidence at the trial of Jurrah, who stands accused of seriously injuring his cousin Basil Jurrah in a fight at the Little Sisters town camp near Alice Springs on March 7 last year.
After telling the Alice Springs Supreme Court that Jurrah was not carrying a weapon on the night the alleged assault happened and had not struck Basil Jurrah, Mr Wilson was challenged by prosecutor Stephen Robson as to why he had contradicted a statement he gave police last July.
"It (the statement) is not true," Mr Wilson said.
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"I was under pressure from the detectives," he said.
"I am suggesting you are lying now," Mr Robson said.
"I am not," Mr Wilson replied.
Mr Wilson, who was in jail for an unrelated matter when questioned by police last year, told Jurrah's defence council Jon Tippett, QC, that he felt he would be locked up for longer if he did not tell police what they wanted to hear.
Mr Wilson agreed with Mr Tippett that detectives asked him the same questions about Jurrah over and over again and only stopped asking when he gave an answer they liked.
In his statement to police, Mr Wilson said he saw the former footballer strike Basil Jurrah three times with a nulla nulla, a type of traditional Aboriginal club.
He told the court police had also pressured him to say other things, including that a woman had twice struck Basil Jurrah, after being told other witnesses had said that.
Since making the statement to police Mr Wilson said he has suffered from anxiety attacks.
The development in the case came as tensions outside court appear to be rising.
During a morning break in proceedings there was a fist fight between two men and in a lunch break, police had to stand between rival groups who were arguing outside court.
Jurrah has pleaded not guilty to the charge of seriously injuring Basil Jurrah.
In earlier evidence Ingrid White, who on Tuesday said that Jurrah had struck her on the head with a nulla nulla, said during cross examination she believed the blow was accidental when she came between the former footballer and another man who were fighting.
The trial, before Chief Justice Trevor Riley, continues.
