Darko Desic, 64, walked into Dee Why police station three Sundays ago to confess to breaking out of a jail in Grafton on the state's north coast on the night of July 31, 1992.

In Central Local Court on Tuesday, he pleaded guilty to escaping from lawful custody.

He's due to be sentenced on October 28.

Desic's case drew worldwide attention as well as support from the northern beaches community where he'd reportedly been living for years.

A GoFundMe crowdfunding site set up by practising psychotherapist Belle Higgins has so far raised $30,000 in an attempt to pay Desic's lawyer and get a roof over the ex-convict's head once he's out of jail.

"He has stayed out of trouble and has had this problem hanging over his head for half his life," she posted.

"Also he has helped our community and been a decent fellow."

Desic was jailed in 1990 for drug supply, serving 19 months of a 33-month minimum term until his escape, allegedly done with a hacksaw blade and bolt cutters.

Upon his return to custody, he resumed serving that jail term, which would have him first eligible for parole on November 1 next year.

Australian Associated Press