Prosecutors plan to build a case against the former chief of the scandal-hit nationalist school operator Moritomo Gakuen on suspicion of unlawfully receiving subsidies from the state and local governments, sources said.

The prosecutors plan to question 64-year-old Yasunori Kagoike, who initially drew attention for winning a huge discount for the purchase of state-owned land in Osaka Prefecture for the construction of an elementary school, the sources said Monday.

Prime Minister Shinzo Abe's wife Akie at one point served as the planned school's honorary principle.

The Osaka District Public Prosecutor's Office's special investigation squad is also probing the dubious land deal that came to light in February.

Separate from the land deal, the prosecutors have received a complaint alleging that Kagoike unlawfully received state subsidies worth ¥56 million ($490,000) for the construction of the elementary school in the city of Toyonaka, which was scheduled to open in April.

The prosecutors have nearly finished questioning people involved in filing for the subsidies. They suspect that Kagoike played a key role in illegally obtaining the funds, the sources said.

Kagoike is also facing another criminal complaint alleging that he fraudulently obtained subsidies from Osaka Prefecture for a preschool.

Following revelations over the questionable land deal, Moritomo Gakuen gave up its plan to open the new elementary school and Kagoike stepped down as head of the school operator in March.

Abe has denied his or his wife's involvement in the sale of the government-owned land. Moritomo Gakuen bought the 8,770-sq.-meter plot in June last year for ¥134 million, roughly 14 percent of its appraisal value, following negotiations with the Finance Ministry's local bureau.