Kiyomi Tsujimoto, a former Social Democratic Party lawmaker who resigned from the Lower House in late March over alleged misuse of her secretaries' state-paid salaries, has returned more than 23 million yen, her office said Friday.

Tsujimoto's office said it contacted the House of Representatives on Monday and paid back 23.3 million yen -- the full salaries of the two secretaries between 1996 and 1998, plus interest.

"It does not mean we have acknowledged it was an act of fraud," an official representing the office said. "We returned the money because we should not have received it in the first place."

Tsujimoto, a former policy board chairwoman of the opposition SDP, allegedly paid only 77,000 yen a month to a woman she registered as a state-funded secretary between October 1996 and March 1997.

Tsujimoto also allegedly paid 50,000 yen a month to another woman between April 1997 and December 1998, despite the fact she had been working as an aide to Kantoku Teruya, a House of Councilors member at the time.

Both women reportedly did almost nothing at Tsujimoto's office.

Masako Goto, an aide to SDP leader Takako Doi, is alleged to have recommended Tsujimoto hire the women, essentially to use their names to claim payment for their salaries.

Tsujimoto has acknowledged that she used the remainder of the salaries to run her office. She did not report the money as a political donation.

Investigative authorities are said to be treating the case as possible fraud and violation of the Political Funds Control Law.

The scandal broke after a weekly magazine ran a story on it March 20. Tsujimoto at first denied the allegations, but tendered a letter of resignation March 26.

When she appeared as an unsworn witness at the Lower House budget committee on April 25, Tsujimoto acknowledged that Goto, Doi's secretary, had introduced her to the two women.

She also said at the time that she was responsible for deciding the terms of their salaries.