By Kaori Kaneko
TOKYO (Reuters) - Japanese Prime Minister Shinzo Abe on Wednesday remained steadfast that he and his wife were not involved in a discount land-sale deal that has seen the opposition call for the resignation of his key ally, Finance Minister Taro Aso.
Abe and Aso have come under fresh pressure over the ministry's admission this week that it had altered documents related to the sale of state-owned land at a steep discount to a school operator with ties to Abe's wife, Akie.
Suspicion of a cover-up could slash Abe's ratings and dash his hopes for a third term as leader of his Liberal Democratic Party (LDP). Victory in the LDP September leadership vote would put him on track to become Japan's longest-serving premier.
Copies of documents released by the finance ministry on Monday showed that references to Abe, his wife and Aso were removed from the ministry's records of the sale to school operator Moritomo Gakuen.
"When you look at the documents even before they were altered, it is clear that my wife and I were not involved," Abe told an upper house budget committee on Wednesday, a statement echoed by chief cabinet secretary Yoshihide Suga.
Abe has said he would resign if evidence were found that they had.
According to the ministry documents, a comment from Moritomo Gakuen citing Akie Abe as telling him, "This is good land so please proceed," was removed. Yasunori Kagoike, the former head of Moritomo Gakuen, and his wife remain in custody after being arrested last July over the deal.
Asked about the reference on Wednesday, Abe said: "I checked with my wife and she says she said no such thing. My wife was neither the person in charge of establishing the school nor Mr Kagoike's boss, so naturally she would not have made such a remark."
Abe and Aso told parliament they had never instructed officials at the finance ministry to alter the documents.
The scandal has caused a stalemate in parliament, with opposition parties boycotting debate on the next fiscal year's budget, potentially delaying reforms to boost long-term economic growth.
On Wednesday, a senior LDP politician told opposition counterpart Kiyomi Tsujimoto that the LDP would call former National Tax Agency chief Nobuhisa Sagawa to testify, a move previously opposed in return for the opposition returning to the budget debate, an opposition party official said.
Sagawa headed the ministry division that submitted the documents before he became tax agency chief in July, an appointment critics saw as a reward for his efforts to diffuse the issue with his statements to parliament last year.
Tsujimoto, who belongs to the Constitutional Democratic Party, countered by asking that Abe's wife appear as well, the opposition party official said. She did not receive a reply.
(This story has been refiled to remove additional letter from name of opposition official)
(Additional reporting by Yoshifumi Takemoto and Elaine Lies,; Writing by Chang-Ran Kim; Editing by Michael Perry)