Updated

The Constitutional Court ordered President Jimmy Morales late Sunday to allow the head of a U.N.-backed anti-corruption commission to return to Guatemala, dealing a blunt rebuke to the leader who has sought in recent weeks to defang the body and its work.

The unanimous ruling by the court's five magistrates marked the second time in as many years that the court has reversed Morales' efforts to keep commission chief Ivan Velasquez out of Guatemala. Velasquez has pressed a number of high-profile graft probes, including one that is pending against the president himself.

Morales announced in late August that he would not renew the mandate of the commission for another two-year term, effectively giving it a year to wind down and end its activities.

A few days later he said that Velasquez, a Colombian national who was traveling in Washington at the time, would be barred from re-entering the Central American nation. Morales called him "a person who attacks order and public security in the country."

Morales' order touched off public protests in support of the body, and multiple appeals were promptly filed with the Constitutional Court.

In issuing its decision Sunday night, the court said its ruling must be obeyed and cannot be appealed.

Morales said earlier this month that he was "not obligated to obey illegal rulings," which observers interpreted as a clear allusion to the court's previous checks on his actions.

Last year, Morales had declared Velasquez persona non grata and tried to have him expelled from the country, but that move was blocked by the Constitutional Court.

Among the investigations that the commission, known as CICIG for its initials in Spanish, has brought in Guatemala was one that led to the resignation and jailing of former President Otto Perez Molina and his vice president. Others have ensnared dozens of politicians, public officials and businesspeople.

Morales is suspected in a case involving more than $1 million in purported illicit campaign financing. In August, Guatemala's Supreme Court allowed a motion by CICIG and Guatemalan prosecutors seeking to lift the president's immunity from prosecution to go to lawmakers. If they approve it, he would be opened up to possible prosecution.

Morales denies wrongdoing, but critics saw his move to wind down CICIG and bar Velasquez as a maneuver to protect himself as well as relatives and associates also in the sights of investigators.

The president had asked the United Nations to designate someone to replace Velasquez, but the world body opted to keep him in charge for the time being, working remotely from abroad. The U.N. defended CICIG and its commissioner, saying the body has played "a pivotal role in the fight against impunity in Guatemala."