Upper House member Tatsuo Tomobe, 72, faces 10 years in prison, the heaviest punishment ever imposed on a lawmaker, as the Supreme Court has dismissed his appeal in a fraud case involving the Orange mutual aid society, judicial sources said Tuesday.

The top court also rejected an appeal by Tomobe's wife, Mikiko, 65, former chairwoman of the the mutual aid society, also convicted in the same case, the sources said.

The Tokyo High Court ruled Dec. 20 that Tomobe defrauded 35 people of a total of 660 million yen in a conspiracy with his wife and four other people in connection with management of the society from 1994 to 1996.