Health officials said on Wednesday medical devices donated by a tycoon for treating liver cancer are still under clinical trials and require careful evaluation before wider use in public healthcare.

Last year, the Li Ka Shing Foundation announced it would donate histotripsy machines for liver cancer treatment to the Chinese University and University of Hong Kong (HKU), as well as the Hong Kong Sanatorium & Hospital.

One of these devices will be relocated from HKU's medical school to Gleneagles Hospital to treat the private facility's patients.

In a joint response, the Health Bureau, the Department of Health and the Hospital Authority said they expect data from the clinical trials to provide scientific evidence for broader applications in the future.

"Clinical trials should be distinguished from clinical services. No clinical service may be provided when a clinical trial is still unfinished," officials wrote in a statement.

When introducing new medical devices, the authority looks at safety and therapeutic effectiveness and the decisions are not influenced by whether treatments are provided or sponsored by manufacturers, officials said.

"The application in the public healthcare system of new drugs and medical devices, and methods for treatment that are still in the clinical trial phase without sufficient clinical data, should be handled in a very careful and prudent manner," they said.

The donated devices have to be listed under the voluntary Medical Device Administrative Control System to ensure medical devices meet safety and quality requirements, officials added.

In response to RTHK inquiries, HKU said 40 patients have been treated over the past six months with the device it has been given and that it is still in the research phase.