TOKYO, June 4 (Xinhua) -- Japan's Ministry of Finance will punish 20 officials for their involvement in the falsifying of documents connected to the controversial heavily-discounted sale of state-owned land to a nationalist school operator, local media reported Monday.

Citing sources close to the matter, a former top bureaucrat at the ministry, Nobuhisa Sagawa, who has since resigned over his alleged involvement in the protracted cronyism scandal, will receive the equivalent of a 3-month suspension, public broadcaster NHK said.

Japan's Finance Minister Taro Aso, of his own volition, will forego his salary as a Cabinet minister for one year to take responsibility for the scandal, that also implicated Prime Minister Shinzo Abe and his wife Akie.

In terms of officials found to be involved in the scandal, a number of them will reportedly have their salaries cut or be disciplined in other ways.

Fourteen sets of documents pertaining to the shady land deal involving school operator Moritomo Gakuen were allegedly changed by ministry officials at Sagawa's orders.

The papers on the land deal were purportedly doctored to fit testimony that Sagawa gave in parliament.

Despite the severity of the scandal and the involvement of senior officials from the finance ministry, prosecutors previously opted not to charge Sagawa or other ministry officials.

In March, Japan's Finance Ministry amid increasing pressure from opposition parties admitted to knowingly altering documents to do with the cut-price land sale.

The admission by the Finance Ministry has intensified calls from the opposition camp for Aso to resign to take responsibility for the scandal.

As the scandal also sees Abe deeply entrenched, some opposition parties have also called for the prime minister himself to step down.

The records that were altered pertain to a shady deal reached to sell a plot of state-owned land to Osaka's Moritomo Gakuen, a nationalist school operator, in June 2016.

The controversial school also had ties to Abe's wife, Akie, who at one point was going to be the school's honorary principal.

Akie soon relinquished the post after the scandal came to light.

Opposition parties said the Finance Ministry had hugely reduced the land price, in part, because of Akie's involvement in the school.

Despite a series of parliamentary boycotts recently due to the issue, the opposition camp has intimated that plans to definitively get to the bottom of the scandal and ensure that those culpable, including Aso, Abe and others, will be publicly held to account.