Shyam Acharya allegedly assumed the identity of a doctor from India - Dr Sarang Chitale - migrated to Australia and was employed by NSW Health between 2003 and 2014.

The scandal prompted the department to launch an independent inquiry into Mr Acharya's actions and health minister Brad Hazzard called for a law change that would allow fakes doctors to be jailed.

Mr Acharya was initially accused of working under the false name at four NSW hospitals: Manly Wyong, Hornsby and Gosford.

But Deputy secretary Karen Crawshaw announced in a statement that Mr Acharya also worked shifts at Royal North Shore Hospital between November 4 and 17, 2012, as well as infrequent shifts at Mona Vale Hospital between January 2008 and February 2013.

NSW Health had fielded 41 individual inquiries from people who believed they may have been treated by Mr Acharya during his time at the four hospitals initially reported.

In addition to the clinical incident reported earlier this month involving the treatment of a patient by Mr Acharya as a member of a clinical team, two further patients had been identified as being treated by the alleged imposter.

"These three incidents will also be referred to the Inquiry," Ms Crawshaw said.

"Of these, three have been confirmed as having been treated by him and their cases will be referred to the Inquiry," Ms Crawshaw said.

Mr Acharya's alleged deception was only uncovered in 2016, when his then-employer, a medical research company, began to question his credentials and reported him to police and the Australian Health Practitioner Regulation Agency.

The Agency has charged him under section 116 of the Health Practitioner National Regulation Law (NSW), which makes it an offence to use a title that could make others believe you are a registered medical professional.

If he is convicted, he faces a fine of up to $30,000. NSW Police have set up a task force to find him.

Shyam Acharya disappeared days before he was due to face court last week over charges of falsely representing himself as a doctor.

Health authorities allege he gained medical registration and was recruited by NSW Health using fake documents.

NSW Health has set up a website to allow members of the public to make submissions to the independent inquiry.

The Inquiry is being led by former Health Care Complaints Commissioner Keiran Pehm and Dr Rob Herkes, Clinical Director of the Australian Commission on Quality and Safety in Health Care.

It will consider the circumstances surrounding the registration, recruitment and employment of Mr Acharya using Dr Sarang Chitale's documentation.

The legislation, policies and practices concerning Mr Acharya's registration by the NSW Medical Board will also be considered.

With Georgina Mitchell and Harriet Alexander