Tatsuo Tomobe, an Upper House Diet member and the main figure in an alleged mutual fund fraud, was arrested on Jan. 29 after the Diet revoked his immunity by unanimous vote earlier the same day.Metropolitan Police Department investigators arrested Tomobe, a 68-year-old former Shinshinto member who is now an independent politician, at St. Luke's International Hospital in Chuo Ward in Tokyo. Tomobe, who had been receiving treatment since Jan. 16 for a stroke he claimed to have suffered, was then transported to the MPD's headquarters for questioning.Tomobe was arrested on suspicion that he conspired to swindle 12 depositors in the Orange Super Fund that was offered by his Orange Kyosai Kumiai out of 145 million yen between July 1994 and October 1996, and that he had not intended to pay the high interest rates promised or repay the principal. Investigators said the mutual aid society collected money from depositors and was run by Tomobe's family members until it folded last December.Police also arrested his wife, Mikiko, 61, who chaired the Orange Kyosai board, their son, Momoo, 29, and three other Orange Kyosai executives earlier in the week on suspicion of involvement in the scheme. Sources said that of the 145 million yen, Tomobe is suspected of generating 53 million yen by soliciting depositors himself, and of having taken 13 million yen of the 53 million yen after he was elected to the Upper House in 1995, they said.At a hastily arranged plenary session on Jan. 29 morning, the House of Councilors unanimously voted to allow Tomobe to be arrested. The chamber then swiftly notified the Cabinet.