The extradition hearing of India-born surgeon Jayant Patel, facing manslaughter charges for alleged botched operations in Australia, was on Friday put off till May 27 by a US judge.

Judge Dennis Hubel consented to the extension after Patel's lawyer Marc Blackman notified the District Court in Portland, Oregon, that his client required more time to 'evaluate his options' before the hearing which was slated for April 18.

Patel, who turned 58 on Friday, has been locked up in a Portland prison since his arrest by officers of the Federal Bureau of Investigation on March 11 and faces a lengthy prison term if convicted of the 16 charges, including manslaughter, grievous bodily harm and fraud.

The surgeon, dubbed as 'Dr Death' by Australian media, at a brief procedural hearing contended that allegations that he killed and injured Australian patients are 'third-hand hearsay' because he wasn't given their medical charts.

His lawyer Blackman attacked the case compiled by Australian authorities relating to the alleged botched operations while director of surgery at Queensland's Bundaberg Base Hospital between 2003 and 2005.

Blackman said the medical charts of patients were not included in the documents Australian authorities compiled and recently handed over to Patel.

"It was just statements - people's second - and third-hand hearsay," Blackman told Judge Hubel.

Patel, whose his legs were shackled, was seen whispering instructions in his lawyer's ear after which Blackman requested Australian authorities hand over the charts, APP reported.

US prosecutor Dwight Holton, acting for the Australian government, said he would contact his Australian counterparts but said the purpose of the extradition proceedings was not to have a 'mini-trial'.

Asked by the judge if he wanted to attend court on April 23 when procedures and issues for the extradition hearing will be discussed, Patel said 'Yes, sir'.