The Consumer Council on Friday urged customers of a shuttered gym chain not to rush into signing documents so they can utilise services of a branch which reopened under a different name.

There was a glimmer of hope for customers of Physical Fitness, after its Wan Chai branch opened its doors on Thursday claiming to provide services for previous members free of charge.

But there's a catch - the gym now operates under the name "HEALTHY", and users are required to sign a consent form authorising the company to collect their personal information.

The consumer watchdog suggested customers may want to wait for a bit before signing the form, as the terms and conditions were "unclear".

"The name of the company operating HEALTHY [is missing]. Hence consumers are unable to ascertain the background information, qualifications and status of the operator," it said.

The council also noted the form stated that HEALTHY has "no obligation" to provide users the services owed by Physical, meaning they may not receive the same product they initially paid for.

Last week, Physical abruptly shut down its 14 branches, but insisted the closure was "temporary" as talks with a new investor were ongoing.

As of 6pm Friday, the council had received 3,666 complaints related to unfulfilled contracts, involving more than HK$123 million.