The right-hand man of slain conman Michael McGurk is set to appear in a Sydney court this morning where it will be decided whether he should give evidence about an alleged bikie associate named Alex Marcello.

Terrence Reddy is in the witness box in a fraud trial in which he has been named as the brains behind a scheme to rip off banks using fake home loan documents.

His business partner in the alleged fraudulent scheme was the head of the Hells Angels bikie gang, Felix Lyle.

Mr Reddy told the NSW Supreme Court yesterday that he feared for his safety if he gave evidence about his dealings with Mr Marcello.

The barrister acting for Perpetual Trustees Victoria, Greg Sirtes, told the court that it might be necessary to make an application to close the court this morning.

Justice Michael Adams is presiding over the case in which Mr Reddy has been giving evidence for five days.

Justice Adams yesterday ordered that Mr Reddy hand over his mobile phone so it could be examined by experts.

The court suppressed the name and telephone number of a person whose text messages were on the phone.

When Justice Adams asked Mr Reddy about when he first met Mr Marcello, Mr Reddy became concerned.

"Any questions you ask me about Marcello are going to be reported in the newspaper tomorrow," he said.

In the months leading up to Mr McGurk's death, Mr Reddy worked for him at Bentley Smythe, which specialised in short-term high-interest loans to desperate people.

The pair also arranged mortgages for people.

This lawsuit dates back to 2005 when Mr Reddy had his own company, Invest One.

Mr Reddy has admitted to forging a client's signature on loan documents and arranging for fake income statements to be provided to banks.

Police said last year that Mr McGurk had been a suspect in a $150 million mortgage fraud syndicate.

Mr Reddy has not faced any criminal charges and he has been given a certificate guaranteeing him immunity from prosecution to allow him to continue his evidence.