Bout, who was called the 'Merchant of Death' in a book about his life, was arrested on a warrant issued by a Thai court on charges of attempted mass murder, police Major General Pongpat Chayaphan told reporters.

'He is now in the custody of the Crime Suppression Division. We will take legal action against him here, before deporting him to face trial in another country, likely the US,' he said.

'We have followed him for several months. He just came back to Thailand today,' Mr Pongpat added. He said police would provide more details on Friday.

A former Soviet air force officer, Mr Bout is wanted by Interpol for allegedly violating UN arms embargoes to several countries in Africa.

He has been accused of supplying notorious Liberian warlord Charles Taylor, Congolese rebels and Taliban militants in Afghanistan.

His life was the inspiration for Nicolas Cage's character in the film 'Lord of War.' -- AFP