Amari initially said he didn't remember receiving cash from the company on the occasions in question and stated that it would've been odd to receive an envelope of cash and put it straight in his jacket pocket. But the minister later conceded that he did in fact receive funds but that one of his aide's mishandled them, as they were not reported in his political funds records.

He said that he instructed his secretary to handle the money correctly, but his secretary failed to do so. Specifically, he was referring to 5 million yen (about 42,000 U.S. dollars) that was given to the minister's secretary, but not logged in Amari's funds reports appropriately.

A follow up article published Thursday, however, quoted sources as saying that Amari directly pocketed cash himself on more than two occasions, to the tune of tens of millions of yen.

The scandal will deal a fresh blow to Abe, who has since retaking office in December 2012, lost three of his ministers following such high-profile funding scandals, with Amari potentially being the fourth and most high-profile.

Abe has, however, intimated that he does not want Amari to relinquish his post, as the scandal has already delayed the process of economic reform-related deliberations in parliament and comes at a time when the prime minister is keenly eyeing the summer upper house election and consolidating his and his party's grip on power, ahead of a possible referendum on constitutional reform, which is dependent on the public's support.

Opposition parties, for their part, are calling for Amari to step down, as well as the prime minister taking responsibility for appointing Amari in the first place.

Japanese Communist Party's secretariat Yoshiki Yamashita said that Amari definitely remembers meeting officials from the construction company in his office, but his claims that his memory is vague about whether he received cash. Yamashita said the claims were nonsensical.

Abe said earlier in the day that it was his duty as prime minister to appoint the right people to his Cabinet, but added that individual politicians regardless of their party allegiance must take responsibility and always be accountable for their own actions so as not to be mistrusted by the public.

The prime minister said Amari should thoroughly investigate the facts and give a full explanation, with his remarks leaving room for Amari's offer to resign being accepted by the prime minister, who, however, may allow his cabinet ally to stay on as minister in charge of TPP.