TAIPEI (Reuters) - Taiwan's government has ordered the island's serving finance minister, his predecessor and four former regulators be investigated to find out whether they bear responsibility for a breach of anti-money laundering rules at the New York branch of state-run Mega Financial Holding's <2886.TW> banking arm. According to a cabinet statement late on Monday, finance minister Sheu Yu-jer and ex-finance minister Chang Sheng-ford will be investigated by Taiwan's Control Yuan, an investigatory agency that monitors government. The agency will determine whether there was "insufficient oversight" in a case that led to a $180 million fine by U.S. authorities.


The finance minister and his predecessor could not be reached immediately for comment on Tuesday in the latest twist in a case that Taiwan's President Tsai Ing-wen has said damaged the island's reputation and created public mistrust about supervision of the financial sector.


The move came after the scandal claimed its first victim in the island's administration on Monday when Ding Kung-Wha, the chairman of Taiwan's Financial Supervisory Commission (FSC), stepped down amid mounting criticism over the watchdog's effectiveness.


Ding is also among the officials facing investigation by the Control Yuan, who served in their respective roles over a period from 2010 to 2016, the cabinet statement said. Also facing investigation are ex-FSC chiefs William Tseng and Chen Yu-chang, and ex-vice chairperson Jennifer Wang.


None of the former FSC officials could be reached for comment.


Preisdent Tsai's opponents on the island said on Monday that ex-FSC chief Ding's departure was a symbolic political gesture that put disproportionate blame on the official, who only assumed his position with the FSC in May of this year.

A veteran of Taiwan's administration not widely known in international finance circles, Ding previously served as chief of the Taipei Exchange and as a finance ministry official.

(Reporting by Faith Hung; Editing by Kenneth Maxwell)