Disgraced pop star Edison Chen Koon-hei has received a death threat in the shape of a bullet.

A letter containing the bullet warned Chen, at the center of a celebrity sex- photos storm last year, to stop making public appearances - or else.

The threat, posted in the US state of Pennsylvania, was delivered to Cable TV yesterday afternoon.

It came 13 days after Chen made two public appearances in Singapore following a year of self-imposed exile in Canada, and just a day after one of the women involved in the internet-photos scandal tried to resurrect her career.

Fallen Twins singer Gillian Chung Yan-tung, 28, tearfully launched a brand of jeans on Tuesday.

A Cable TV spokeswoman said an A4-sized envelope with eight US stamps was received around 5pm. It contained a smaller white envelope, which held a typed letter and the bullet. "We hope Edison Chen will take this warning seriously, otherwise his personal safety will be threatened," it read.

The writer said Chen, 28, had been given a chance to appear in Singapore, but would not get another.

The spokeswoman said the station reported the case to the police immediately. She would not speculate as to why the station was targeted.

The police special crime squad has launched an investigation.

Secretary for Security Ambrose Lee Siu-kwong said Hong Kong is governed by the rule of law and violent or intimdating activity will not be tolerated.

Chen's record company, East Asia, expressed shock, but would not co

mment because it is now a police matter. Police have classified the case as "bullet found," according to a spokesman.

Cable TV aired an exclusive interview with another victim of the sex photo scandal, actress Cecilia Cheung Pak-chi, 28, on the same day Chen was in Singapore.

Cheung's manager said she was unaware of the threat, and declined to comment further.

Gillian Chung last week gave her first interview since the scandal to TVB. Tsang said security staff at the station have been warned to remain vigilant.

A source close to Chen said the actor-singer had earlier received a threatening phone call. That was one of the reasons why he had last month given evidence from Vancouver in the case of a Hong Kong computer technician charged with uploading the photos.

The trial of Sze Ho-chun, 23, is due to begin on April 6 at Kwun Tong Magistrates' Court.

(CRI/Agencies March 12, 2009)