HONG KONG (AP) — Hong Kong Chief Executive John Lee said police will investigate suspicious applications from people seeking to withdraw from the city’s organ donation system, condemning the alleged attempt to damage the program as shameful.

The city’s organ donation registration system received nearly 5,800 withdrawal applications in the five months since December, when the government raised the possibility of establishing an organ transplant mutual assistance program with mainland China. More than half of the withdrawal applications were found to be invalid, either as duplicate applications or coming from people who had never opted in.

At a regular media briefing Tuesday, Lee pointed to those who withdrew their applications without ever registering, calling the moves suspicious.

“I severely condemn those who attempt to cause damages to this noble system which saves lives through organ donations,” he said. “This is a shameful act.”

Hong Kong, a former British colony that returned to China in 1997, has a separate system for matching donated organs to patients and does not have any standing mechanism to share cadaveric organs with institutions in mainland China. Cross-border organ transplants have been permitted on a case-by-case basis.

Under an opt-in system, Hong Kong currently has more than 357,000 registrants in the financial hub that houses 7 million people. Organ donations have been met with resistance in both Hong Kong and China because of an ingrained cultural desire to keep bodies intact.

The government issued a strongly worded statement Monday, saying it could not rule out that a small number of people made withdrawal attempts in a bid to undermine the reputation of the system and to increase the administrative burden. Without naming any platforms or any individuals, it said a small number of people had distorted the virtue of organ donation by promoting the idea that donors should scrutinize the identity of the recipients online. Some also urged others to withdraw from the system, it added.

On Hong Kong’s Reddit-like forum LIHKG — where pro-democracy supporters discussed strategies for the 2019 anti-government movement — some users were skeptical about the proposed system. Others posted a link for making withdrawals from the register.

The Hong Kong government floated the proposal after a baby girl underwent the city’s first transplant using a heart donated from mainland China in December. It said the organ assistance program under consideration could be activated immediately after medical personnel could not match a donated organ with a suitable patient locally.

The political row over the proposed mutual assistance program reflected some Hong Kongers’ distrust of China’s health system, as well as their grievances toward Beijing, which has cracked down on the city’s pro-democracy movement with a sweeping national security law.

Hong Kong's medical standards are considered some of the highest in the world. While China's medical system has advanced over the past few decades, many Hong Kongers remain skeptical about its health care services. Allegations of forced organ harvesting in China, particularly targeting minorities in detention, have added to concerns about a cross-border organ cooperation.

In 2015, Beijing ceased transplanting organs taken from executed prisoners in response to human rights concerns and later provided data to the international community to show it was fighting illegal organ transplants.