Liberal Democratic Party lawmaker Shokei Arai, who allegedly made huge profits through questionable stock transactions, on Monday defied a party leader's demand that he leave the LDP.

LDP Secretary General Koichi Kato met Arai on Monday morning and urged him to leave the party, saying his testimony before the Diet last Friday has deepened suspicions that he may have been involved in illicit trading with Nikko Securities Co. However, Arai rejected the demand, saying leaving the party would mean the end of his political career, according to Kato. LDP executives want him to leave the party to prevent the scandal from adversely affecting Diet proceedings on budgetary and other bills.

Last Friday, Arai answered questions as an unsworn witness before the Lower House Budget Committee on allegations that he received profits from Nikko Securities Co. through dubious equity investments. Arai admitted he made about 41 million yen through securities trading in an account that he created under the name of an acquaintance. However, he insisted he did nothing illegal and denied that he demanded unfair profits from the brokerage.

Many lawmakers, including his LDP colleagues, said they were not convinced by Arai's explanations. Opposition parties as well as the Social Democratic Party -- one of the LDP's two non-Cabinet allies -- are demanding that Arai and Nikko executives be summoned to the Diet as sworn witnesses.