Burundi on Sunday accused former colonial power Belgium of ordering the assassination of independence hero and Crown Prince Louis Rwagasore in 1961, a move likely to further poison ties between the two countries.

A government statement said Belgium was the "true backer of the assassination of Rwagasore", in the first direct accusation over the murder by Bujumbura, which said it plans to probe the six-decade old incident.

The statement said that Brussels "has yet to explain itself" over the killing of Rwagasore, who played a key role in Burundi's anti-colonial movement.

Rwagasore was named prime minister in the run up to independence, but was shot dead a month later by a Greek assassin accompanied by three Burundian members of a pro-Belgian party at a hotel in the capital - a little over a year before independence was achieved in July 1962.

He is one of Burundi's most beloved heros, with his name gracing stadiums, schools and roads across the country.