Prosecutors plan to question Liberal Democratic Party lawmaker Takao Koyama as early as today on suspicion he received over 10 million yen in bribes from scandal-hit industrial insurance provider KSD, investigative sources said Sunday.

KSD founder and former president Tadao Koseki, 79, allegedly gave the money to Koyama, a 57-year-old House of Councilors member, in 1996 in return for the lawmaker's submitting questions in Parliament that were helpful to KSD's business, they said.

The Tokyo District Public Prosecutor's Office, which has already questioned some KSD officials over the case, will investigate whether the allegations constitute a criminal act, the sources said.

Koyama has told Kyodo News he has never taken money from KSD, which offers industrial accident insurance for small and midsize companies.

During Diet panel sessions in November 1995 and April 1996, Koyama called on then Labor Ministry to extend the period that foreign workers invited to Japan as trainees can remain in the country. An organization set up by Koseki accepts such trainees.

At a March 1996 parliamentary panel session, the lawmaker also demanded the government cut inheritance taxes, which would have benefited small business owners.

Koyama served as parliamentary vice labor minister between July 1998 and October 1999.

Koseki has been indicted for breach of trust and other charges involving misuse of the group's money.