Opposition politicians have alleged that the buyer of the land - a right-wing operator of private schools - was able to clinch the sale at such a favourable price because of his ties to the Abe family. It said one document originally noted that the school operator was involved with a powerful pro-Abe political lobby, Nippon Kaigi, of which Abe was vice chairman, but that comment had later been deleted.
"We'll continue the investigation to get to the bottom of why this happened - I want Finance Minister Aso to take responsibility for that", Mr Abe said yesterday.
One such reference was to Akie's visit to the school at the heart of the suspected scandal.
The Finance Ministry also confirmed on Friday the death of an official linked to the scandal.
Allegations against Ms Abe, for her involvement with Moritomo Gakuen, an operator of ultraconservative schools that was able to purchase government land in Osaka at a fraction of its value, first emerged early past year, but resurfaced after the revelation that official documents related to the sale had been changed.
"What is important now is to make everything clear", Suga said at a news conference. "If we don't make clear who did this, trust in the LDP will waver".
Asked about his responsibility in the case, including any intention to resign as the head of Kobe Steel has said he would over a data-falsification scandal at the steelmaker, Aso said: "We can not draw a simple comparison between Kobe Steel and this case". Aso suggested that the document tampering was limited to a handful of bureaucrats.
Already public anger is growing.
Trump says Wilbur Ross, EU to discuss tariffs, trade barriers
President Donald Trump last week that Canada won't become a transit station for offshore steel and aluminum into the U.S. market. Trudeau also took Canada's case to US cable channels on Monday with appearances on MSNBC and CNN.
Plane crash in Nepal leaves at least 49 dead, 22 injured
The pilot circled twice in a northern direction and was asked again if things were okay, and the pilot gave the same response. In 2012, a plane carrying trekkers to Mount Everest region hit a bird and crashed in Kathmandu , killing all on board.
Willian is Chelsea's main man ahead of Barca showdown
On Friday he recalled the experience he says he carries in his heart. "I think this is part of our job. However, since the turn of the year, Villa have been in top form with eight wins in ten league games.
Abe said Aso will not step down.
Abe and Aso will try to contain the damage until the furore subsides.
The 77-year-old Aso apologised for his ministry's actions but said he had no intention to resign.
Suspicions of a cover-up could slash Abe's ratings and dash his hopes of a third term as leader of his Liberal Democratic Party (LDP). Yukio Edano, leader of the constitutional Democratic Party of Japan, said the document doctoring by the ministry "shakes the foundation of Japan's democracy".
The response of senior LDP lawmakers such as party Secretary-General Toshihiro Nikai will be critical to any effort to protect Aso, as well as to containing the fallout for Abe.
Japan's Prime Minister Shinzo Abe (L) and his wife Akie at Haneda Airport in Tokyo, Japan February 28, 2017.
Factional maneuvering to replace Abe - either before the September election or at that point - would surely heat up if Aso resigned. Possible Abe successors including former foreign minister Fumio Kishida, as well as Ishiba, have spoken about the need to fix Japan's ballooning debt with fiscal consolidation. On the trade front, it must deal with U.S. President Donald Trump's protectionist policies.
Japan also faces the security worry of North Korea's missile and nuclear threat.