His family says the 30-year-old Briton died in police custody at a Malaysian airport.
Callum Luxton was driving through Kuala Lumpur International Airport to Phuket, Thailand, when he died last Saturday.
Local police say Callum, from Rochdale, was arrested after which “became unconscious while documenting the arrest”.
Callum’s family are devastated and without answers Manchester Evening News reported.
His dad Roy said: “It’s just a nightmare and we’re not getting answers. We don’t know anything and now we have to get him back home.
“No one tells us anything. We don’t know how he went. You could say he was safe at the airport, of course not.”
Roy said Callum’s family had no idea what was happening and his phone was also missing.
“We just want to know how he died… it’s ridiculous.”
The family was notified by a policeman who knocked on their door on Monday evening.
The police officer told the family that an incident had occurred and Callum’s bag had disappeared.
The New Straits Times quoted Selangor police chief Datuk Hussein Omar Khan as confirming that Callum died in custody.
Khan said Callum was arrested for criminal mischief, criminal damage to property, voluntarily causing hurt and obstructing a public servant.
Khan said: “At around 1.30pm, police arrested the suspect who was traveling from the UK to Phuket in Thailand with a transit stop at KLIA Terminal 1. He behaved aggressively and disturbed the peace there.
“While preparing the documentation, the suspect lost consciousness, prompting officers to call the KLIA medical team.
“The doctor provided first aid, but the suspect was pronounced dead at the scene.”
A Foreign, Commonwealth and Development Office (FCDO) spokesman told The Sun: “We are aware of the death of a British national in Malaysia and are cooperating with the local authorities and his family in the UK.”