PORT-AU-PRINCE, Haiti (AP) — An ombudsman office in Haiti denounced Thursday what it called the “unacceptable slowness” of the Haitian investigation into the assassination of President Jovenel Moïse nearly two years after he was killed.

The Office of Citizen Protection, an independent government agency that investigates complaints against public institutions, noted that while the case has barely budged in Haiti, US authorities have arrested 11 suspects and convicted one of them already.

One defendant was sentenced last month in Florida, where prosecutors have alleged there was a broad plot among conspirators in both Haiti and Florida to hire mercenaries to remove Moïse and benefit from lucrative contracts from a successor administration.

In Haiti, the ombudsman office also called for better protection for Walter Wesser Voltaire, the judge investigating the case. Voltaire is the fifth judge assigned to the case, with four previous ones being dismissed or resigning for personal reasons.

Voltaire on Thursday declined to speak with The Associated Press, saying the investigation is confidential and that he would hold a press conference when ready.

A previous judge assigned to the case told the AP that his family asked him not to investigate the case because they feared he would be killed, while another judge stepped down after his assistant died under murky circumstances. Judges in Haiti not only oversee legal proceedings but also investigate cases.

Prime Minister Ariel Henry stressed on Thursday that the investigation into the slaying is continuing, but did not provide details.

“For my government, it’s important that Jovenel Moïse find justice,” he said. “I am doing everything in my power to help the judicial system move forward.”

Meanwhile, the ombudsman office demanded that an international body help Haiti’s Ministry of Justice with the investigation into the July 7, 2021 killing of Moïse, who was shot 12 times at his private home.

“Many individuals denounced in this assassination are still on the run,” the office said.

On Thursday, María Isabel Salvador, UN special envoy to Haiti, said the call continues for those responsible for Moïse’s slaying to be brought to justice.

“His assassination submerged Haiti into a deeper political crisis which has been exacerbated by an unprecedented breakdown of security, with criminal armed gangs imposing a regime of terror and violence in most parts of Port-au-Prince,” she said.

More than 40 other suspects are languishing in one of Haiti’s crumbling prisons, including at least 18 former soldiers from Colombia accused of participating in the slaying in which Moïse’s wife, Martine, also was injured.

Earlier this month, Martine repeated her call for the International Criminal Court in the Netherlands to investigate the slaying. She also filed a lawsuit in late June against the suspects in the case, seeking unspecified damages for her family and a trial by jury.

In a June 26 tweet, Martine wished her slain husband a happy birthday, noting he would have been 55 years old. She called for an in-depth investigation, writing, “The truth will come out. Justice will be served.”