UNITED NATIONS (Reuters) – Guatemala said it had notified United Nations Secretary-General Antonio Guterres that it would end a U.N.-backed anti-graft commission on Tuesday – eight months earlier than expected – over accusations it had interfered in internal affairs.

The International Commission Against Impunity in Guatemala, or CICIG, was established over a decade ago with the authority to conduct independent investigations and work with the country’s prosecutors.

Guatemalan President Jimmy Morales had said in August he would not renew the organization’s mandate, which was due to expire in September 2019. Days later, he banned CICIG head Ivan Velasquez, a hard-charging Colombian prosecutor, from re-entering the country.

Working with Guatemala’s attorney general, CICIG had sought to prosecute Morales, a former comedian, in 2017 over illegal financing allegations linked to his election campaign two years earlier. That move followed separate CICIG graft probes into members of the president’s family.

Guatemalan Foreign Minister Sandra Jovel met with Guterres in New York on Monday and handed him a letter informing him of the government’s intention to end the agreement that had established CICIG.

“It is regrettable that the Secretary-General, in a bid to maintain one person in the position, sacrificed the legitimacy of the commission,” Jovel told a news conference after the meeting, referring to Guterres’ decision to stand by Velasquez.

“Therefore we reported to the Secretary-General that within 24 hours the agreement (that was struck to create CICIG) will be terminated by the Guatemalan government,” she said.

Guterres “strongly rejects” the content of the letter, a spokesman for the secretary-general said in an emailed statement, adding that the United Nations expected Guatemala’s government to “fulfill its legal obligations under the agreement” until the CICIG mandate ends in September.

“The Secretary-General recalls the important contribution of CICIG to the fight against impunity in Guatemala,” it said.

The foreign-led CICIG is unusual among U.N. bodies for its powers to bring cases to prosecutors, and many politicians in Guatemala consider it to be a violation of national sovereignty. Anti-corruption activists credit it with cleaning up government.

Last month, the Guatemalan government revoked visas and immunity for 11 CICIG investigators and two relatives.