Schapelle Corby could be released immediately from an Indonesian prison if a recommendation by the country's Supreme Court to halve her sentence is accepted, the convicted drug smuggler's lawyer says.

Corby's lawyer Iskandar Nawing told Fairfax newspapers the country's Supreme Court has recommended 10 years be cut from her sentence.

"If the president signs off on it, with the time Corby has served already she will be eligible for parole. I will immediately make the arrangement based on the clemency."

The recommendation was handed to Indonesian President Susilo Bambang Yudhoyono last July and its contents have been the subject of much speculation.

Under Indonesian law, an application for presidential clemency must be lodged first with the Supreme Court, which assesses the application before providing guidance to the president to accept or reject.

Corby was arrested six and a half years ago after more than four kilograms of marijuana was found in her bodyboard bag at Bali airport.

She has lost a succession of legal appeals, and a clemency request to Indonesia's president is her last chance.

Neither the Supreme Court nor Dr Yudhoyono's state secretariat would comment to Fairfax on Mr Nawing's claims, nor confirm when Dr Yudhoyono would make a decision.