As the year that saw the Democratic Party of Japan (DPJ) win a national election by a landslide draws to a close, Prime Minister Yukio Hatoyama and DPJ's Secretary General Ichiro Ozawa are currently both embroiled in scandals involving illegal donations that threaten to tarnish the reputation of the ruling party.

Hatoyama is under investigation over 300 million yen (3.5 million dollars) in political funds that were incorrectly declared between 2005 and 2008, and then last month it emerged that his mother Yasuko loaned him around 900 million yen (10.5 million dollars) between 2003 and 2008. Donations to politicians from individuals are not allowed to exceed 1.5 million yen (17,000 dollars) per year.

An aide was dismissed for his role in faking the sources for the 300 million yen donations, and is now under investigation. Hatoyama dismissed the aide when the revelations came to light. It is alleged that he faked the source of donations, using such techniques as claiming the money was given to Hatoyama by people who were deceased at the time.

Hatoyama has been questioned about the issue in parliament, and has said that now is "not the time" for him to step down. Meanwhile, Yasuko Hatoyama is set to face prosecutor's questions over her alleged illegal donations to her son.

However, Hatoyama will likely avoid questioning by prosecutors over political funds records that were allegedly cooked to conceal dubious donations, media reports said Wednesday.

The premier and his associates are expected only to provide investigators with a paper explaining his position on the allegation, Kyodo News reported, citing unspecified sources.

Yasuko Hatoyama is the first daughter of the founder of tyre manufacturer Bridgestone Corp., meaning the prime minister is from one of the wealthiest families in the country.

Hatoyama can only receive a 500,000 yen fine over the funding scandal, but even that is unlikely as the blame for the misdeed has been placed on the aide, who covered up where the money came from. But the political fallout could be much more costly.

It also emerged last month that another DPJ heavyweight, Secretary General Ichiro Ozawa, did not report political donations worth of 2.3 million yen between fiscal 2004 and 2007. It is also alleged that Ozawa's aides asked for 100 million yen in illegal donations from a construction company in 2004 and 2005.

Ozawa was forced to step down as the leader of the DPJ in May, after it emerged in March that he had falsely reported on donations from Nishimatsu Construction Co. At that time, Takanori Okubo, a former chief accountant of Ozawa's who was working as one of his secretaries, was arrested for his role in hiding the source of the funds.

The DPJ was swept to power in an August election after almost 55 years of uninterrupted Liberal Democratic Party (LDP) governance. During its time in power, the LDP gained a reputation for closed-door politics and in its last decades of governance, scandals were often reported.

Since coming to power, as part of its attempt to change politics, the foreign ministry under Katsuya Okada has set about revealing secret agreements between the Washington and Japan that were signed in the 1960s and 70s allowing the U.S. military to carry nuclear weapons on its soil. The move to reveal details of the agreements has proved popular with the public in the only country in the world to have suffered a nuclear attack.

In perhaps the most notorious scandal of the LDP era, Prime Minister Kakuei Tanaka was arrested in 1976 after it emerged that his office and a number of other key government figures and institutions - had taken bribes from U.S. aerospace company Lockheed Martin. The U.S. company used its influence to force Japanese All Nippon Airways to purchase its planes rather than those of rival maker McDonnell Douglas.

Many analysts see the victory of the DPJ in summer elections as a condemnation of the style of politics played out by the LDP and a demand from voters to see a more transparent system of government.

In its manifesto, the DPJ stated that it aims to "end public distrust in politics," and the consequences of the current inquiries into Hatoyama and Ozawa's donations will be watched by voters to judge whether the party can live up to its promises.