LAGOS, Dec 31, 2007 (AFP) - A Nigerian federal commission on Monday said it plans to investigate 31 of the country's 36 state governors for possible fraud between 1999 and April 2007.

The head of investigations in the Independent Commission on Corrupt Practices, Tunde Ogunshakin, said the probes came in light of the delivery of relevant documents to the office of the Chief Justice of Nigeria.

'This followed a series of petitions sent to the commission by members of the public during the governors' tenure,' Ogunshakin told the Nigerian NAN news agency.

'These allegations border on corruption, money laundering and other forms of abuse of office,' he said.

The governments of both Nigerian President Umaru Yar'Adua, elected this year, and his predecessor launched anti-graft campaigns and panels in the west African country regularly blacklisted by Transparency international as one of the most corrupt on the continent.

Nigeria is the world's eighth largest petroleum exporter, but its Economic and Financial Crimes Commission believes that more than 400 billion dollars in potential state funds went astray between independence in 196O and 1999.

The commission's head, Nuhu Ribadu, was relieved of his functions Thursday to ostensibly pursue a study course, in a move that sparked charges of political manipulation.