Thailand's foreign ministry has conveyed a letter of condolence to Russian Foreign Minister Sergey Lavrov over the murder of the Russians in Pattaya, the Thai ministry said.

A Thai official expressed deepest condolences, confirmed the case is being taken seriously, and assured full cooperation with Russian authorities.

Earlier, the relatives of the two siblings, 22-year-old Diana Nazimova and 17-year-old Roman Nazimov, reported that their remains are to be cremated in Thailand, noting that their mother opposes the death penalty for the accused as too lenient.