A prominent human rights attorney has quietly parted ways with the International Criminal Court to protest what he sees as an unjustified failure of its chief prosecutor to indict members of Venezuelan President Nicolás Maduro ’s government for crimes against humanity, The Associated Press has learned.

The Chilean-born Claudio Grossman, a former law school dean at American University in Washington and past president of the Inter-American Commission on Human Rights, was appointed special adviser to ICC Prosecutor Karim Khan in November 2021. In that unpaid position, he advised Khan on the deteriorating human rights situation in Venezuela.

In a harshly worded email last month to Khan, Grossman said his ethical standards no longer allow him to stand by silently as Maduro’s government continues to commit abuses, expel foreign diplomats and obstruct the work of human rights monitors from the United Nations — without any action from the ICC.

“I can no longer justify the choice not to take correspondingly serious action against the perpetrators of the grave violations,” Grossman wrote in an email rejecting an offer by Khan’s office in September to renew his contract.

A copy of the email, which has not been made public, was provided to the AP by someone familiar with the ICC investigation into Venezuela. A phone call by Khan asking Grossman to reconsider also failed, according to the person on the condition of anonymity to discuss the politically sensitive investigation.

Following AP’s inquiries with Khan’s office, Grossman’s name was removed from the court’s website listing him as a special adviser.

“The Prosecutor is extremely grateful to Professor Grossman for the expertise and work he has rendered,” the prosecutor’s office said in a statement without addressing Grossman’s stated reasons for cutting ties with the court based in The Hague, Netherlands. Grossman declined to comment.

The pressure on Khan to indict Venezuelan officials, including Maduro himself, comes as he battles allegations of misconduct with a female aide and the threat of U.S. sanctions over his decision to seek the arrest of Israeli Prime Minister Benjamin Netanyahu for alleged war crimes in Gaza.

The Rome Statute that established the court took effect in 2002, with a mandate to prosecute war crimes, crimes against humanity and genocide — but only when domestic courts fail to initiate their own investigations.

Calls for faster progress in the court’s only ever investigation in Latin America have grown louder as Maduro tightens his grip on power, preparing to be sworn in for a third term Jan. 10 following an election marred by serious allegations of ballot box fraud and a post-election crackdown. More than 2,000 people were arrested and 20 killed following the vote.

The U.S. and even some fellow leftist leaders in Latin America have demanded authorities present voting records, as they have in the past, to refute tally sheets presented by Maduro’s opponents showing their candidate, Edmundo González, prevailed by a two-to-one margin.

Many in Venezuela’s opposition have complained that the ICC is applying a double standard, moving aggressively to seek the arrest of Netanyahu and Russia’s Vladimir Putin for atrocities in Gaza and Ukraine while showing undue leniency with Venezuelan officials Khan has been investigating for more than three years.

“There is no justification whatsoever for the inaction,” González and opposition leader María Corina Machado wrote in a recent letter to Grossman and 18 other special advisers to the court appealing for their help.

“What is at stake is the life and well-being of Venezuelans,” they added in the letter, which was also provided to the AP by the person familiar with the ICC investigation. “This unjustifiable delay will cast legitimate doubts about the integrity of a system of accountability that has been an aspiration for the whole world.”

At the request of several Latin American governments, Khan three years ago opened an investigation into Venezuelan security forces’ jailing, torture and killing of anti-government demonstrators. At the same time, he promised technical assistance to give local authorities an opportunity to take action before the ICC, a tribunal of last resort.