A former Macquarie fund manager has been given a prison sentence for attempting to avoid ASIC investigations by trying to flee the country.

The NSW Supreme Court found that Oswyn De Silva, a former portfolio manager at Macquarie Bank, was running from allegations of wrongdoing by the corporate watchdog when he tried to flee the country earlier this month.

He was given a prison sentence on Thursday, after earlier pleading guilty in the NSW Supreme Court to being in contempt of court.

However, the length of the sentence is yet to be determined, with the court requesting information on what medical treatment NSW Corrective Services will be able to provide De Silva while in custody.

The 36-year-old former portfolio manager was diagnosed as being HIV positive in 2005, and the court on Thursday was told he was taking antibiotics but required further medication which he did not have.

De Silva was apprehended by Australian Federal Police as he tried to board a flight in Perth on March 1, just days after he was ordered by the NSW Supreme Court not to leave Australia.

The Australian Securities and Investments Commission (ASIC) had sought the orders as it was investigating trading De Silva had engaged in between 2006 and 2007 while at Macquarie Bank.

In his sentencing remarks on Thursday, Justice George Palmer said he had concluded that De Silva's attempt to leave the country was a premeditated effort to escape the ASIC allegations.

The court found that De Silva's contrition for his actions was not sincere and was only expressed once he had been caught.

"Mr De Silva has not accepted responsibility for his real actions," Justice Palmer said.

While acknowledging imprisonment would cause De Silva emotional stress due to his medical condition, Justice Palmer said it was important that orders of the Supreme Court were obeyed.

Earlier this week, De Silva, a resident of the United Kingdom, told the court he had fallen into cocaine abuse after he left Macquarie with a confidential severance package in 2008.

Justice Palmer acknowledged De Silva had been through a "dark and troubled" period of his life, and said he hoped he would emerge successfully.

De Silva will be required to report to police daily before Justice Palmer delivers the terms of the custodial sentence on March 24.

- AAP