Japan's main opposition party demanded Thursday that a son of Prime Minister Yoshihide Suga be summoned to parliament as a witness over allegations he treated senior bureaucrats of the communications ministry to expensive dinners.

The Internal Affairs and Communications Ministry has been conducting a probe into four senior officials over potential ethics code violations after they were reported to have been wined and dined last year by Suga's eldest son, who works at a company operating satellite broadcasting services.

Among the four, Yoshinori Akimoto, director general of the information and communications bureau, previously told the House of Representatives' Budget Committee that he had no recollection of talking with the prime minister's son, who works for Tohokushinsha Film Corp., about satellite broadcasting.

His ministry issues a broadcast license to a unit of Tohokushinsha Film. The National Public Service Ethics Law prohibits central government officials from receiving favors from stakeholders.

But weekly magazine Shukan Bunshun released online Wednesday what it claimed was an audio recording of the conversations between the son, Akimoto and another Tohokushinsha official, in which the son repeatedly mentions satellite broadcasting.

Kuniaki Hara, a senior ministry official, told parliament Thursday that Akimoto had admitted that a voice on the recording was his but said the director general does not remember discussing satellite broadcasting.

The main opposition Constitutional Democratic Party of Japan has accused the ministry of attempting to "systematically conceal" what happened and demanded further investigation. The CDPJ has threatened to boycott the deliberations of the Diet committee unless its questions are answered by Friday.

The party also called for two other ministry officials to appear for questioning -- Yasuhiko Taniwaki and Mabito Yoshida, both vice ministers for policy coordination.

In addition to Akimoto, Taniwaki and Yoshida, Hironobu Yumoto, deputy director general of the information and communications bureau, also dined with Suga's eldest son.

Hiroshi Moriyama, Diet affairs chief of the ruling Liberal Democratic Party, said his party will work to ensure Taniwaki and Yoshida "fulfill their accountability."

Suga has said he was not aware of the dinners.

The prime minister's son became acquainted with some of the four senior bureaucrats when he served as a secretary to his father, who was internal affairs and communications minister between 2006 and 2007, according to the weekly magazine.

==Kyodo

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