jovenel moise mural
© ReutersPeople walk past a wall in Port-au-Prince, Haiti, with a mural depicting President Jovenel Moïse, who was shot dead last week.
Items found at Christian Emmanuel Sanon's house include bullets, gun parts and US drug agency hat.

Police in Haiti say they have arrested a new suspect in the assassination of the country's president, Jovenel Moïse - a Haitian living in Florida who arrived on a private plane in June allegedly to act as a middleman between the alleged hitmen and the plot's unnamed masterminds.

As Haiti descended ever deeper into a dangerous political chaos, with notorious gang leader Jimmy "Barbecue" Cherizier calling on Haitians to "mobilise", the motive for the killing of Moïse remained unknown.

The latest suspect was identified by police as Christian Emmanuel Sanon, a Haitian in his 60s living in Florida who describes himself as a doctor and has accused his homeland's leaders of corruption.

"He arrived by private plane in June with political objectives and contacted a private security firm to recruit the people who committed this act," Haiti's police chief, Léon Charles, said, describing a private Venezuelan security company based in Florida called CTU.

The wife of at least one Colombian arrested for his part in the attack, Francisco Uribe, has claimed CTU offered her husband around $2,700 (£1,950) a month to work in Haiti. According to newly disclosed details, CTU also bought the tickets to Haiti for a number of Colombians implicated in the plot.

The head of Haiti's police, Léon Charles, accused Sanon of working with those who plotted and participated in Moïse's killing, which plunged the nation of more than 11 million people into uncertainty.

It remained unclear, however, whether Sanon was the alleged key mover - although some news sources suggested he had ambitions to be president - or how a former bankrupt in Florida had either financed the plot or planned to seize power.

Four men have made claims to lead the country's government since the assassination, including the acting prime minister, Claude Joseph, and Ariel Henry, whom Moïse appointed prime minister two days before his death.

The police chief said that among the items found by officers at Sanon's house in Haiti were a hat with the logo of the US Drug Enforcement Administration. Moïse's killers had claimed to be DEA agents when they assaulted his home.

Also reported found were 20 boxes of bullets, gun parts, four vehicle licence plates from the Dominican Republic, two cars and correspondence with unidentified people.

Laurent Dubois, a Haiti expert and Duke University professor, said questions over Moïse's assassination could remain unanswered for a long time. "There are so many potential players who could be behind it," he said. "There is going to be some jockeying for positions of power. That is one big worry."

The intervention by Cherizier, who leads the G9 and Allies gang federation - which critics say has been used for politically motivated killings - has added to an already febrile atmosphere, with Cherizier railing against police and opposition politicians whom he accused of colluding with the "stinking bourgeoisie" to "sacrifice" Moïse.

"It was a national and international conspiracy against the Haitian people," he said in a video address, dressed in khaki military fatigues and sitting in front of a Haitian flag.

"We tell all bases to mobilise, to mobilise and take to the streets for light to be shed on the president's assassination."

Haitian authorities claim a 28-member hit squad stormed Moïse's presidential compound in the early hours of last Wednesday before shooting him dead - a sensational narrative coming under increasing scrutiny, both in Haiti and overseas.

Charles said Sanon was in contact with a firm that provides security for politicians and recruited the suspects in the killing, and that he accompanied several of the alleged hitmen on a flight into Haiti.

The gunmen's initial mission was to protect Sanon, but they later received orders to arrest the president, Charles said. "The operation started from there," he said, adding that an additional 22 suspects joined the group and that contact was made with Haitian citizens.

Eighteen Colombians have been arrested so far, along with three Haitians. Charles said five of the suspects were still at large and at least three had been killed, including Capador.

"They are dangerous individuals," Charles said. "I'm talking commando, specialised commando."

Charles said that after Moïse was killed, one of the suspects phoned Sanon, who then got in touch with two people police believe to be the masterminds. He did not identify them or say if police knew who they are.

Colombian police said on Monday that they could not share any hypothesis about the murder of Moïse.

"We cannot construct any hypothesis," said General Jorge Luis Vargas, head of the Colombian national police. "We respect the judicial autonomy of the Haitian state and its authorities."

However, Vargas said Colombian police were investigating the activities of a Haitian man named Dimitri Herard, who served as Moïse's head of security. Herard transited through Colombia multiple times earlier this year, Vargas added, during trips to Ecuador and the Dominican Republic between January and May.

Colombian police are investigating Herard's activities during his visits, Vargas said. However authorities have yet to establish a direct link between Mr Herard and the captured former soldiers, officials said.

He said Haitian authorities obtained the information from interrogations and other parts of the investigation. He added that police were working with high-ranking Colombian officials to identify details of the alleged plot, including when the suspects left Colombia and who paid for their tickets.

Sanon has lived in Florida, in Broward County and in Hillsborough County on the Gulf Coast. Records show he also lived in Kansas City, Missouri. He filed for bankruptcy in 2013 and identifies himself as a doctor in a video on YouTube titled "Leadership for Haiti".

In the video, he denounces the leaders of Haiti as corrupt and accuses them of stripping the country of its resources, saying: "They don't care about the country, they don't care about the people."

He claims Haiti has uranium, oil and other resources that have been taken by government officials.

"This is a country with resources," he said. "Nine million people can't be in poverty when we have so much resources in the country. It's impossible ... The world has to stop doing what they are doing right now. We can't take it any more. We need new leadership that will change the way of life."

Sanon has posted little on Twitter but has expressed an interest in Haitian politics. In September 2010, he tweeted: "Just completed a successful conference in Port-au-Prince. Many people from the opposition attended." A month later, he wrote: "Back to Haiti for an important meeting regarding the election. Pray for me for protection and wisdom."

While the streets were calm on Sunday, government officials worry about what lies ahead and have requested US and UN military assistance.