Shyam Acharya allegedly posed as doctor Sarang Chitale to enter Australia and work at Manly, Hornsby, Wyong and Gosford hospitals between 2003 and 2014.
Authorities are trying to find a man accused of stealing the name and credentials of a qualified doctor to enter Australia and work in NSW hospitals for more than 10 years.
Shyam Acharya allegedly posed as Sarang Chitale to work at Manly, Hornsby, Wyong and Gosford hospitals between 2003 and 2014, and at private medical research company Novotech between June 2015 and September 2016.
He was also able to get Australian citizenship.
Acharya has been charged by the Australian Health Practitioner Regulation Agency and the case is due in court in April, but it's not clear if he will face court as he is believed to have fled the country.
The current court case against Acharya will not deal with how he was allegedly able to enter and leave Australia or obtain citizenship in the name of the other doctor, NSW Health said on Tuesday.
The Department of Immigration and Border Protection is investigating the matter, a spokeswoman said in a statement to AAP.
Watch the Health Minister speak about the case:
Premier Gladys Berejiklian acknowledged NSW Health must claim responsibility.
"There's no doubt there's a huge number of questions around his registration criteria, his qualifications, all those issues which I know now, many doctors whether they're from overseas or local, go through so many processes now to demonstrate their qualification. Clearly this didn't happen 11 years ago."
She said since that time, more "stringent" guidelines had been introduced, but "the fact that it went on for 11 years adds to the surprise and shock that many people are feeling today".
"Clearly we need to make sure at a state level we've done everything we can," she said.
She said that the NSW health minister would raise the issue at the next COAG meeting to determine what went wrong and what needed improving to ensure that people posing as doctors could never practice.
However Ms Berejiklian added that the matter was also a federal one.
"This is really an issue about how this person got through our border protection system at a national level with fake passport ID and put himself up to be something he clearly isn't,” she said.
"It's unacceptable that he entered our country with a fake passport, fake ID, got through the border protection system, and put himself up for something that he wasn't."
Watch the AMA president speak about the case:
NSW Health would not say whether Mr Acharya had any medical experience before working in Australia.
Ms Crawshaw said Mr Acharya’s status as a junior doctor with limited registration meant he was subject to supervision.
She said Australia's Health Practitioner Regulation Agency advised NSW Health it was investigating Acharya in 2016 - more than two years after he left the state's public health system.
He has since been charged with a breach of the Health Practitioner Regulation National Law, and if convicted faces fines of up to $30,000.