Japan's justice minister, who has admitted past links with organized crime, resigned on Tuesday just three weeks into the job, citing "health problems", the government said.

Keishu Tanaka was brought into the cabinet at the start of the month as part of a reshuffle aimed at shoring up Prime Minister Yoshihiko Noda's shaky administration.

But a little over a week later he was forced to admit a connection to Japanese crime syndicate yakuza after a tabloid magazine revealed he had once acted as matchmaker for a senior mobster.