A criminal complaint has been filed against Japanese Prime Minister Sanae Takaichi, alleging that she violated political funds control laws by receiving donations exceeding the legal maximum.

A reminder of Takaichi's scandal-laden ruling Liberal Democratic Party, or LDP, the complaint was filed on Thursday by Hiroshi Kamiwaki, a constitutional law professor at Kobe Gakuin University in Japan, according to Xinhua News Agency.

The professor said a local chapter of the LDP in Nara prefecture, represented by Takaichi, received a 10 million yen ($64,400) donation from a company in August 2024, which exceeded the 7.5 million yen limit stipulated in the political funds control law for donors of that size.

Kamiwaki also filed a separate complaint dated Wednesday against Japanese Defense Minister Shinjiro Koizumi for the same type of violation.

An LDP chapter in Kanagawa prefecture led by Koizumi received a 10 million yen donation from another firm, also surpassing the 7.5 million yen cap.

Both chapters said they returned the donations, with Takaichi's chapter claiming they "misjudged" the donor size, according to Kyodo News.

The complaints came amid the LDP's ongoing slush fund scandal, first revealed in 2023, in which some LDP party factions allegedly instructed member lawmakers to sell political fundraising event tickets beyond their assigned quotas without recording the amount as revenue in political funding reports.

They are alleged to have funneled the surplus back to lawmakers as kickbacks, creating off-the-books funds.

Seven of the senior officials Takaichi appointed after taking office in October have been linked to the scandal.

Critics said her ambiguous stance on the scandal suggests limited willingness to push for fundamental reform.

Takaichi said at the Nov 26 party leaders' debate that rather than tightening restrictions on corporate and organizational donations, it would be preferable to reduce the number of seats in the Diet, Japan's parliament.

Tetsuo Saito, the Komeito party leader, expressed doubt about Takaichi's response, saying, "I couldn't help but feel uncertainty about her commitment to political reform."

Takaichi explained in a Diet meeting on Wednesday that she made the remark because there was very little time left in the party leaders' debate, and she wanted to quickly shift the discussion to the issue of "reducing the number of Diet seats".

She stated that improving the political funding system to earn the public's trust and reducing Diet seats as a form of "self-reform" are equally important, and that she never intended to suggest that one is more important than the other.

On Thursday, Kiyomi Tsujimoto, a senator for the Constitutional Democratic Party, said on a BS-TBS television program that Takaichi's election as prime minister was driven by the return of politicians involved in "black money".

She explained that former members of the anti-mainstream faction led by former prime minister Taro Aso fought to regain power, adding that members of the former Abe faction and lawmakers implicated in the political donations scandal were also seeking a comeback.

"These forces generated enormous momentum and developed into a power struggle," Tsujimoto said.

At that moment, Takaichi, backed by right-wing circles, rode that wave, and with these factors aligning, became prime minister, Tsujimoto added.

Yet Takaichi has faced heightened scrutiny over money, especially her publicity spending.

Takaichi spent 83.84 million yen on publicity and campaign promotion for the 2024 LDP presidential election, according to Mainichi Shimbun.

In comparison, former Japanese prime minister Shigeru Ishiba, who won the 2024 LDP presidential election, spent only 420,000 yen on the leadership race, while his publicity expenses for the whole year were only around 12 million yen.

Xinhua contributed to this story.