Japan's education minister is set to launch a new investigation into documents that reportedly show Prime Minister Shinzo Abe pushing officials to give favorable treatment to a university program being run by a friend.

A former top bureaucrat argued Abe's advisers and the Cabinet Office put undue pressure on the Education Ministry last year to quickly approve the establishment of the veterinary medicine department of Okayama University of Science.

The high-ranking officials wanted to see the university open the department in April 2018, according to Kihei Maekawa, former vice minister of the ministry, who spoke to the Tokyo Shimbun daily.

It was the "intent of the prime minister" to open the new section, and the timing was "what the highest level of the prime minister's office has said," according to leaked documents that Maekawa has verified.

The university is operated by the Kake Educational Institution, who chairman is Kotaro Kake, a longtime friend of Abe. Since the prime minister first took office in 2012, he and Kake have had dinner on at least nine occasions and played golf together four times.

Abe and other top officials have repeatedly questioned the authenticity of the documents, which supposedly show that Abe's office pressed government officials to approve the school's application.

Kake had already obtained the city-owned property for free in the western Japanese city of Imabari.

Opposition demands testimony

Opposition lawmakers are demanding for Maekawa to testify in parliament. The retired education ministry official recently acknowledged the existence of the documents and the political pressure that went along with it. But Abe and his supporters - notably Chief Cabinet Secretary Yoshihide Suga - have so far rejected this account, dismissing Maekawa's claims, and using harsh language in criticizing his private life.

"We accept the people's voice sincerely and will conduct an additional investigation" into the authenticity of the documents, Education Minister Hirokazu Matsuno said during a news conference. He noted that an earlier investigation in May found no evidence that the documents existed.

Critics point out that the Kake school plan had been repeatedly rejected in the past due to a lack of demand. They say the project only began to move forward after Abe's government eased requirements for veterinarian schools.

Opposition leaders welcomed the new probe, but demanded that the government conduct a thorough investigation.

"What matters is the quality of the investigation," opposition Democratic Party leader Renho Murata said. "We will be closely watching whether it is predetermined."

Abe faced a serious blow in January last year, whhen his economy minister was forced to quit over graft claim.

Neighboring South Korea has recently faced a massive political scandal over the former President Park Geun-hye and her close friend Choi Soon-sil. Park was ousted out of office in December to face accusations of corruption and influence peddling.

bik/rc (AP, dpa)