OSAKA -- The Kinki Postal Administration Office in March paid for a meeting in Osaka of a group of special post office heads connected with an election violation case surrounding Kenji Koso, a newly elected House of Councilors lawmaker in the ruling Liberal Democratic Party, investigative sources said.

The office also paid for a business liaison conference for special post office heads that was held immediately after the private organization's meeting, the sources said Thursday.

Meanwhile, one of the post office heads in attendance at the meeting reportedly later told police that he was told to destroy documents related to the election. The request came when police began investigations the day after the election, the sources said.

Police believe the private organization that led Koso's campaign was united with the public organization under the Public Management, Home Affairs, Posts and Telecommunications Ministry, the sources said. The organized destruction of evidence related to the violations is believed to have been carried out within the two organizations, they added.

Koso served as the head of the Kinki Postal Administration Office between June 1998 and July 1999.

On Sunday, police arrested the 59-year-old head of the Kinki office, Tsuyoshi Mishima, on suspicion of violating the Public Offices Election Law by using his influence to urge postmasters to support Koso.

Mishima's office oversees 7,000 post offices in six western Japan prefectures.

During the meeting of special post office heads, held the morning of March 7 in a hall in Osaka, Mishima allegedly urged around 100 postmasters to join a support group for Koso as well as conduct activities intended to increase the number of Koso's supporters, according to early investigations.

The liaison conference was held at 1 p.m. the same day in the same venue.

While the two organizations are separate, most of the members belong to both. And the same person usually heads the local branches of both organizations.

Koso, who said neither he nor his campaign staff asked Mishima to support his election campaign, denied involvement in the case and ruled out any possibility of resigning.

However, Koso could be stripped of his lawmaker status if Mishima is convicted of election violations under the "guilty by association" stipulation in the election law.

If a former government employee runs in a race held within three years of their resignation, election violations by their successor and the successor's subordinates invalidate the candidate's election and prevent them from running for the same constituency for five years.

Meanwhile, in summer 2000, a senior official from the Kinki region support group asked Tsunehiko Nishida, head of the Kinki office's general affairs department, to cooperate in soliciting supporters for Koso, the Kyoto Prefectural Police found Thursday.

Nishida was arrested Aug. 16 on suspicion on using his official position to illegally canvass votes for Koso.

The senior official of the support group is a former official of the Kinki post office and also serves as president of the group of special post office heads.

Koso garnered 480,000 votes in his first run for public office. He resigned from the ministry in July 1999.

Police allege Nishida asked more than 10 senior officials from post offices under the Kinki Postal Administration Office's jurisdiction to round up votes for Koso.

Nishida, who was promoted to his current job in July, was serving as general affairs section chief when he allegedly made the vote-canvassing call in early June at a gathering of post office officials at the Osaka Central Post Office.