Lagos - The former head of Nigeria's anti-corruption watchdog has been facing death threats and should be given protection from the government, Human Rights Watch (HRW) said Wednesday.

Nuhu Ribadu was removed from his position as the head of Nigeria's Economic and Financial Crimes Commission (EFCC) in 2007 shortly after the commission indicted a politician close to Nigerian President Umaru Yar'Adua.

Ribadu told the New York-based HRW that he had received telephone death threats and had shots fired at him in late September.

"The campaign of intimidation against Mr Ribadu appears aimed at silencing a key voice in the crucial fight against corruption in Nigeria," said Georgette Gagnon, Africa director at HRW. "The Nigerian government and President Yar'Adua need to protect Ribadu and anyone else who dares to speak out against the corrupt and powerful."

Under Ribadu, the EFFC indicted hundreds of people, including a former inspector general of police and former state governors.

Corruption is viewed as a major problem in oil-rich Nigeria, Africa's most populous nation, and Yar'Adua promised to crack down on graft.

However, HRW said that the despite Yar'Adua promising to allow the EFFC to pursue a "zero-tolerance" policy on corruption, his government had undermined anti-corruption efforts. (dpa)