A Democratic Party of Japan leader Seiji Maehara promised Wednesday he will produce more information about shady financial links between Livedoor Co. founder Takafumi Horie and a son of Tsutomu Takebe, the secretary general of the Liberal Democratic Party, but only if the ruling bloc agrees to launch an official Diet investigation.

Despite growing public calls for the DPJ to substantiate its allegation, Maehara repeated his party cannot reveal information that would identify the number and holder of a bank account allegedly controlled by Takebe's son, to which the DPJ claims Horie ordered staff to transfer 30 million yen in August.

DPJ officials said the party fears the ruling LDP will not act on the information unless there is an official Diet probe, which is unlikely considering the ruling bloc's majority, and thus veto strength, in the legislature.