Alessandro Coatti, 42, worked for Britain’s Royal Society of Biology as a science policy officer whose job included giving evidence to parliament, before leaving that post in 2024 to travel in South America.

Part of his body was found in a suitcase on a riverbank on April 6.

Other remains were later found in other locations.

Coatti had arrived in Santa Marta, a city that acts as a gateway to idyllic palm-lined Caribbean beaches and the snow-capped Sierra Nevada mountain range, as a tourist.

The police said he was lured by a gang that planned to rob him to an abandoned house in the city, through a dating app for the LGBTQ community.

Santa Marta’s mayor Carlos Pinedo said Sunday that four people suspected of his murder and dismemberment had been arrested in raids in the Colombian capital Bogota, the second city of Medellin as well as in Santa Marta and the town of Arjona, near the port city of Cartagena.

At a press conference yesterday, Santa Marta police chief Colonel Jaime Rios said that the police had received a tip-off, which led them to a house where traces of blood were found.

“Through arduous investigative work, interviews were conducted, biological traces belonging to the victim were collected, and security camera footage was analysed, which were all key to solving the case,” he said.

The gruesome killing of Coatti, described by colleagues at the Royal Society of Biology as a “passionate and dedicated” scientist, caused shock in Colombia.

Pinedo had offered a reward of 50 million Colombian pesos (US$12,000) for information leading to the capture of his killers.

Rios said the reward had led to the breakthrough in the investigation.

The Sierra Nevada mountains are home to a drug-running paramilitary gang known as the “Conquistadors of the Sierra Nevada”.

It is not known if they had any hand in Coatti’s murder, but they have been linked to the murder and dismemberment of others in recent years.