According to the publication, Chiang Chin-liang, 43, was involved in a ream of about 30 crimes including the murder of a politician, arms smuggling, and a prison escape. He was sentenced to 20 years in prison after being arrested during a shootout with police, the magazine wrote. Cabinet spokesman Su Jun-pin confirmed the premier traveled to the Indonesian island last December with individuals involved in tourism development in his home county of Nantou. Chiang reportedly heads a foundation active in local tourism. Wu was a lawmaker for Nantou at the time.

After the reports provoked widespread discussion, Wu came out to tell the media that Chiang had bettered his life and was now doing useful things for society. Chiang participated in the trip as the chairman of a tourist market in the city of Tsaotun, the premier said. Wu denied the financing of the trip was illegal.

The allegations threatened to damage both President Ma Ying-jeou's campaign to reform the ruling Kuomintang's image and the Dec. 5 county and city elections.

The magazine published pictures of Chiang standing between Nantou County Magistrate Lee Chao-ching, who also participated in the Bali excursion, and Wu's wife. Lee said he didn't know Chiang's background at the time. Chiang serves as chairman on a Lee re-election support committee, reports said.

The convicted gangster's presence on the five-day trip was linked to the distribution of benefits from the local gravel trade and to the election of a new Nantou County Council speaker and vice speaker after the election, said Lee Wen-chung, the opposition Democratic Progressive Party candidate for county magistrate.

The leading DPP member said organized crime was trying to expand its power by directly influencing the choice of top county officials.

Opposition lawmakers said the incident showed that the premier was the wrong man to rid Taiwanese society of gangster influence.

DPP legislator Lawrence Kao wondered how Wu could chair government meetings about law and order, and how he could help in getting rid of interference by organized crime in baseball.

Ma, in his capacity of KMT chairman, should investigate the incident and cancel Lee Chao-ching's candidacy, said DPP Chairwoman Tsai Ing-wen.

The KMT's image has already been damaged by allegations that candidates for its recently elected Central Standing Committee distributed gifts to voters, leading to plans for a complete re-election later this month.

In addition, four KMT lawmakers saw their election canceled over the past year as courts found them guilty of vote buying.