Cambodia has formally rejected an extradition request from the Thai government for its fugitive former premier, deepening a row between the two countries.

The rift between Cambodia and Thailand deepened after Phnom Penh appointed Thaksin Shinawatra as an economic adviser.

Thaksin, who was toppled in a bloodless coup in 2006 and sentenced to two years in jail in absentia, arrived in Cambodia on Tuesday.

Thai diplomats gave extradition documents to Cambodia's officials, but then received a note which formally denied their request.

"The condemnation of Thaksin Shinawatra is logically the consequence of the military coup d'etat in September 2006 which resulted in his removal from the post of prime minister, while he was overwhelmingly and democratically elected by the Thai people," said the Cambodian letter.

"Our diplomatic note answering them is nothing beyond rejecting the extradition request," Cambodian Foreign Minister Hor Namhong told AFP.

Cambodia has repeatedly vowed to refuse any request from Thailand to extradite Thaksin.

MVZ/SC/AKM