The suspect, Segarra, 37, is accused of killing David Bernat, a businessman who is from the same region of Catalonia in Spain.

He was arrested in Cambodia late last week and was returned to Thailand on Monday.

The police also have asked the court to reject his bail request, although he hasn’t met with either relatives or Spanish Embassy officials for that purpose yet.

Segarra, who has been detained in Bangkok Remand Prison since yesterday, denied the allegations and did not say anything during the interrogation, according to acting chief of Metropolitan Police Pol Lt-General Sanit Mahat-avorn.

“But that’s not a problem, police have ways to prove his wrongdoing,” he said, declining to detail such methods. Police believe Segarra committed the crime alone but they are trying to find out whether he had any accomplices.

Asked about his Thai girlfriend Pridsana Saenubon, Sanit said police were collecting information and evidence to prove her involvement. “Now she is under police protection [as a witness],” he said.

Sanit said police found a textbook on dismemberment in Segarra’s bedroom but suspected he might have bought it from a neighbouring country.

“But we don’t know anything about that as the suspect hasn’t said anything yet,” he said.