Justice minister Keishu Tanaka of Japan, who took office three weeks ago, is under pressure to resign over past ties to organised crime.
Mr Tanaka does not deny a report in a tabloid magazine that he once had ties to a Yakuza gang, but says that was 30 years ago.
However, several gang members have told a reporter that Mr Tanaka still had ties to the Yakuza until two years ago and once acted as matchmaker for a senior member.
The BBC reports Mr Tanaka, 74, was admitted to hospital on Sunday, complaining of feeling unwell.