A Haitian migrant climbs the Mexico-US border fence near the El Paso border crossing, in Ciudad Juarez, Chihuahua state, Mexico on Thursday. Photo: AFP

Haitian Prime Minister Ariel Henry, who has been asked to appear for questioning in connection with the July slaying of the country's president, on Saturday slammed what he called "diversionary tactics" used by investigators.

Investigators say they want to ask Henry about alleged conversations he had just a few hours after the murder of Jovenel Moise with a former government official wanted in connection with the murder.

Late Friday, prosecutor Bed-Ford Claude asked Henry to appear on Tuesday to answer questions about the calls. Police are still actively searching for the former official, Joseph Felix Badio, who worked in the justice ministry's anti-corruption unit. "These diversionary tactics, designed to create confusion and prevent justice from calmly running its course, will not stand," Henry said.

"Those who are truly guilty, the masterminds of the odious assassination of president Jovenel Moise and those who ordered it, will be found, brought to justice and punished for their actions."

Badio's phone was allegedly tracked to the area near Moise's residence when he called Henry twice in the early hours of July 7, after the president was assassinated. Given that a judge has already been assigned to handle the probe, Claude in theory does not have the power to summon anyone, but he justified his request by citing the "extreme seriousness" of the investigation, which is in the "national interest."

A prime minister legally cannot be questioned unless the president authorizes it, but in the wake of Moise's slaying, Haiti does not have a president.

Claude specified that Henry's participation in questioning would be voluntary "given the restrictions in place" due to his post.

The office of the Haitian government's human rights ombudsman, Renan Hedouville, said it was shocked by the news of the alleged phone calls.

"Ariel Henry must resign and make himself available to prosecutors," said a letter signed by Hedouville.

So far, 44 people - including 18 Colombians and two American of Haitian descent - have been arrested in connection with the inquiry into the assassination of Moise.