Suspicion about Prime Minister Shinzo Abe's alleged favoritism toward school operator Kake Gakuen deepened further on Friday after a potentially compromising document was unearthed at the agriculture ministry.

The discovery gives further credibility to a similar document that was first reported by the daily Asahi Shimbun on Tuesday. Ehime Gov. Tokihiro Nakamura has claimed that the document obtained by Asahi was drafted by a prefectural official on April 2015 but the prefecture doesn't have a copy because it was written simply as a memo and was later discarded.

The latest file found at the agriculture ministry, obtained by The Japan Times, said that Abe was behind a deregulation project which gave the green light to a school operator run by his close friend to build a new veterinary department in Imabari, Ehime Prefecture.