An Ontario man is now reportedly the prime suspect in the double murder of fellow Canadian Francesca Matus and her American boyfriend in Belize.

According to Channel5Belize.com, John Deshaies, 54, initially helped with the search for Matus, 52, and Drew DeVoursney, 36, after they vanished on April 25.

Sources in the country said Deshaies — who appears to work in construction and has been living in the country for three years — rented the lower half of Matus’s sprawling beachside mansion.

Deshaies, who had been taken into custody over an alleged theft at a casino in Placencia, will reportedly be charged on Friday.

After that, he will be returned to Corozal, where Matus lived.

“We have one person we believe can assist us in our investigation,” was all police Senior Supt. Dennis Arnold would tell local reporters.

Detectives have backed away from their initial theory that the slayings were a robbery gone awry, and are exploring if it was a land deal that soured.

Matus — a real estate investor — lived half the year in Belize and was a popular figure among the ex-pat community of 300 strong that gathered at a local watering hole for gossip and fun.

It was at Scotty’s Bar and Grill where she and her boyfriend of several months were last seen.

Their bodies were discovered Monday in a sugarcane field. Their hands had been duct-taped and an autopsy revealed they were strangled.

While keeping tight-lipped, cops have hinted that the killer — or killers — are ex-pats.

Earlier in the week, Arnold said as much: “I believe that members in the community, their community, know exactly what was happening.”

In addition, investigators revealed that Matus had been threatened — but not with death.

Meanwhile, WSB-TV Atlanta — where DeVoursney was from — is reporting that the FBI is now assisting Belize police in the probe.

Handyman Jaime Olivarez told Channel5Belize.com he would see the rugged former marine, Matus and Deshaies.

He said of Deshaies: “Every morning he goes out and he doesn’t come back until the night or evening. Mister John lives over there but I don’t know about his family.”

A memorial service was held Thursday at Scotty’s bar and a memorial service is planned for Saturday at Matus’s Keswick, Ont. home.