A Finance Ministry official asked Osaka-based school operator Moritomo Gakuen last year to lie about how waste was removed from property it had purchased from the ministry in a controversial deal, a senior official admitted Monday.

The admission by the high-ranking official during a session of the Upper House Audit Committee will deepen suspicion over the heavily discounted land sale to the ultranationalist school operator that once had close ties with Akie Abe, the wife of Prime Minister Shinzo Abe.

During the committee session, Mitsuru Ota, head of the ministry’s Financial Bureau, said one of its officials called the attorney representing Moritomo Gakuen on Feb. 20 last year and asked the school operator to fabricate a story that “several thousands of trucks” were used to remove a huge amount of waste from the property in Toyonaka, Osaka Prefecture.

The attorney reportedly turned down the ministry’s request.

Ota, who didn’t identify the official in question, said the made-up story is “different from facts” and now the ministry “deeply apologizes for it.”

NHK on Wednesday first reported the unidentified official’s request for Moritomo Gakuen.

Citing anonymous sources, NHK also reported that Osaka-based prosecutors have already learned of the request. The prosecutors are reportedly investigating the ministry on suspicion of breach of trust in connection with the dubious land sale.

During a Lower House Budget Committee session on Feb. 17 last year, Nobuyuki Fukushima of the Democratic Party pointed out that 12,200 cubic meters of soil should have been removed from the grounds and 11,100 cubic meters of new soil should have been brought in if the amount of waste claimed by the ministry was actually removed.

It would take “4,000 dump trucks” to transport that amount of soil, Fukushima said, asking if the ministry confirmed that number of vehicles were actually used.

Nobuhisa Sagawa, then the head of the Financial Bureau, didn’t answer Fukushima’s question during the session. But the unidentified official apparently requested Moritomo Gakuen to cook up a story that would match the amount of waste claimed by the ministry.

The official made the request just three days after Fukushima’s questioning in the Diet, according to Ota.

The land plot was sold to Moritomo Gakuen for ¥134 million in June 2016, an 86 percent discount from its estimated value of ¥956 million. Justifying the discount, the ministry said tons of waste was reportedly buried there.

No convincing evidence has been found to back up the ministry’s claim so far, and opposition lawmakers have argued the discount was given because of Moritomo Gakuen’s ties with the first lady, who once served as the elementary school’s honorary principal.

If Osaka-based prosecutors raid the ministry and arrest officials, it would deal a huge blow to Abe and his administration.

However, investigative authorities are, in general, very conservative and will not file a charge against anyone with a high profile unless they are fully convinced that a court will hand down a guilty verdict.

Abe has denied any involvement by him or his wife in the land deal.