Nigeria's Economic and Financial Crimes Commission (EFCC) has started to investigate the source of 9.8 million U.S. dollars secretly kept in the house of a former senior official of the national oil corporation, the anti-graft agency said Friday.

Andrew Yakubu, former group managing director of the Nigerian National Petroleum Corporation (NNPC), has admitted ownership of the recovered money during interrogation, the EFCC said in a statement.

The 9.8 million dollars and another 74,000 pounds cash were recovered on Feb. 3, following a raid by the anti-graft agency in Yakubu's house in the northwestern state of Kaduna, according to the statement.

The former official, who served as head of the national oil corporation from 2012 to 2014, had been standing trial over allegations of money laundering in Nigeria since last June.

He told investigators that the money recovered in his home was a gift from unnamed persons, the EFCC said.

He is still being held for further interrogation, the agency added.

The huge cash, described as "suspected proceeds of crime" by the EFCC, was hidden in a safe hidden inside the former official's home located in the slums of the Sabon Tasha area.

A number of high-powered former Nigerian officials have been arrested on corruption charges in recent months, giving a boost to the country's fight against corruption.

All eyes have been on the national oil corporation as one of the worst offenders as billions of dollars were suspected to have leaked out of government coffers for almost two decades now. 

source: Xinhua