TOKYO (REUTERS) - Japan's environment minister denied wrongdoing on Friday after a newspaper said his office appeared to have received improper funds, the latest embarrassment for Prime Minister Shinzo Abe.

Three of his ministers have quit over funding and election scandals since he took office in late 2012.

The Asahi newspaper said a branch of Abe's Liberal Democratic Party in Shizuoka prefecture, headed by Environment Minister Yoshio Mochizuki, collected 1.4 million yen (S$15,918) from a logistics company which had received government funds.

This would violate a law which bans a company from making political donations within a year of a decision to be awarded government subsidies.

"I received the donation from the company without knowing it was receiving subsidies and I think it was not illegal," said Mochizuki. "I have returned the 1.4 million yen, considering morality."

Top government spokesman Yoshihide Suga also defended the minister, saying he had returned the funds as soon as he found out there was a possible conflict.

On Thursday, Education Minister Hakubun Shimomura denied a report by a weekly magazine that he illegally received political funds, just days after the farm minister resigned over similar allegations.

The accusation against the education minister might especially sting because Shimomura, whose ministry is also in charge of preparing for the 2020 Tokyo Olympics, is considered close to Abe.