A Spanish chef has admitted to killing his Colombian surgeon lover and dismembering his body before dumping parts in a landfill on Koh Phangan and his head and other parts in the sea, police say.

Daniel Sancho Bronchalo, 29, was taken to the Koh Phangan police station on Friday for questioning in connection with the disappearance of Edwin Arrieta Arteaga, 44, a Colombian national. He eventually admitted to murder, said a source familiar with the investigation.

The suspect is the son of the Spanish actor Rodolfo Sancho Aguirre and actress Silvia Bronchalo. A well-known chef in his home country, he also has a YouTube channel. The victim operated a successful plastic surgery clinic in Monteria, Colombia.

Police found more evidence believed to be human body parts after searching a hotel room thought to be where the killing took place, police said on Saturday.

Forensic officers collected samples of hair, fat and tissue from the room’s drain and sent them for testing.

A police examination of security video from various places on the island showed Mr Sancho was linked to the case. The Spanish man was the last person seen with the victim before the human body parts were found.

Mr Sancho had gone to the Koh Phangan police station on Thursday night to report that Mr Arrieta was missing. This came after news spread that some human body parts had been found.

Trash collectors on Thursday discovered body parts, including a pelvis and intestines, inside a sack at a garbage dump on the island.

More body parts were found on Friday in a black plastic bag at the same location. The bag contained two legs, a black T-shirt, a pair of shorts and a pair of boxer shorts.

Relatives of Arrieta told police that he had been in a relationship with Mr Sancho for more than one year. The pair had gone to Koh Phangan to attend a Full Moon party. When Arrieta’s relatives were unable to contact him, they contacted Mr Sancho but the Spanish man said he hadn’t seen him yet.

A police source said that during questioning, Mr Sancho told investigators that he had taken Arrieta to his room. He claimed the man wanted to have sex with him, but he refused.

In a fit of anger, he punched his friend, causing the victim to fall and lose consciousness after hitting his head on a bathtub. Mr Sancho decided to cut the body into 14 pieces and put some parts into a travel bag. He also put some parts into plastic bags and dumped them in a garbage bin.

He took the travel bag to dump in the sea at Salad beach near his hotel. After that he returned to his room and checked out at 9am on Thursday.

He later went to a Full Moon party with two women he knew at the hotel. After returning from the party, he went to the police station where he filed a missing person report that his Colombian friend had disappeared.