TAIPEI -- The manager of a Taiwan TV station at the center of a controversy over footage it aired of a gangster threatening to kill a rival resigned Monday, saying the episode had compromised his professional values.

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TVBS initially said the video that aired early last week - complete with the gangster brandishing a deadly array of firearms - was mailed to the station, but later acknowledged that two of its reporters had filmed it themselves.

The reporters have since been fired.

The airing of the footage underscored the highly competitive nature of Taiwan's television news market, in which seven round-the-clock cable stations pull out all the stops in the battle for viewer loyalty and advertising revenue.

TVBS's general manager, Leo Tao, announced Monday he was stepping down, saying he was bowing to a demand by the independent National Communications Commission to leave his post.

The station was earlier fined New Taiwan dollars 2 million (US$60,000; euro46,000) by a communications watchdog.

Leo said in a statement he felt "severe pain" over the video's airing, adding that it "ran contrary to professional values and failed to live up to society's trust."

"I will resign to take full responsibility for it," Lee said in the statement.

He also called on unnamed politicians to cease their attacks against TVBS.

In recent days members of the ruling Democratic Progressive Party have mounted a relentless campaign against it, with some calling for it to be closed indefinitely.