Multiple Victorian doctors are under investigation, suspected of breaching the chief health officer's COVID-19 directions.
The state's Department of Health is understood to have significant concerns about a small number of doctors undermining the vaccine rollout, including falsifying whether the vaccine was administered or giving fake exemptions.
"While the regulation of general practitioners is a matter for the federal government, we will always protect Victorians and Victoria's health system from fraudulent practice," a departmental spokesman said in a statement.
"We are investigating reports of GPs breaching CHO directions and are actively considering all options, including compliance, enforcement and regulatory avenues."
Two Maidstone general practitioners last month had their registrations suspended over concerns about fake vaccination exemptions.
Crowds seen by AAP and neighbours of often-unmasked people would line up with little social distancing at the practice of Dr Michael Keng Sin Lee and Dr Yee Wah Eva Wong for hours.
"Public protection is our number one priority. Our message is clear: we believe vaccination is a crucial part of the public health response to the COVID-19 pandemic," the Australian Health Practitioner Regulation Agency and the Medical Board of Australia said in a statement.
AAP has also found a comment posted under an article on the Royal Australian College of General Practitioners website by a person with the same name as Dr Lee touting the use of hydroxychloroquine, a dismissed treatment for COVID-19.
"For GP a to help we need hydroxychloroquine, zinc , Zithromax, dexamethasone. These have been used successfully in US for early cases of Covid. Also PPE," the post by Dr Michael Keng Sin Lee on August 5, 2020, reads.
AAP approached Dr Lee for comment and received no response.
"When providing care, advice or sharing information online, registered health practitioners have a professional obligation to provide information that is evidence-based, in line with the best available health advice, and is consistent with public health messaging," AHPRA said in its statement.
The RACGP is the industry body for general practitioners and its president Karen Price says it expects the highest standard of professionalism and care from its members.
"We actively provide advice and support to GPs so that they are informed on the latest clinical evidence and guidance, including in regard to caring for patients with COVID-19," she said in a statement.
Reports by GPs of being pressured into giving vaccination exemptions recently saw Victoria tighten the rules around obtaining one.
Exemptions can only be issued on specific medical grounds, including a severe reaction to a COVID-19 vaccine or a severe acute medical illness that allows for a temporary delay in vaccination.
From October 29, Victorians have to fill out an exemption form with the Australian Immunisation Register to obtain an exemption certificate via the myGov website.