Labour and welfare chief Chris Sun has assured there is a strict system to screen people applying to enter Hong Kong under the top talent scheme.

He said on Saturday that officials have not found anyone providing fake credentials, following earlier reports of people allegedly forging documents to cheat their way into a local university.

"We have built in a very, very robust system to make sure that all the qualifications submitted to us are true, and can be verified," Sun told reporters after a radio programme.

"For submissions, say, from mainland China, it's a mandatory requirement. They have to verify via a third-party system, or they have to verify directly with the institution granting them the qualifications."

The administration had said visa holders under the scheme will be given an extra two months to apply for an extension.

Extension approvals will be granted based on various factors, including the person's income, tax payments and time spent in Hong Kong.

The labour minister pointed out that officials do not currently have an estimate on how many individuals would have their visas extended.