Nigeria's anti-graft agency on Tuesday filed corruption charges against a former justice minister over a $1.3bn dollar oil scandal involving international majors Shell and Eni.

Mohammed Adoke was arrested last month on arrival from the United Arab Emirates where he had been detained on a Nigerian warrant in connection with one of the West African state's biggest-ever corruption scandals.

"We have filed multiple corruption charges in Abuja against Mr. Mohammed Adoke in respect of the Malabu oil deal. The former minister will appear in court soon," Tony Oriade, spokesman for Nigeria's Economic and Financial Crimes Commission, told AFP.

Oriade said Adoke, a former attorney general, was accused of money laundering and collecting a bribe worth 300m naira to broker the sale of lucrative offshore oil block OPL245 to Shell and Eni.

Both oil companies deny any wrongdoing in the case dubbed the "Malabu scandal" after the key company involved in the deals.

Adoke was alleged to have collected the bribe from a businessman, Abubakar Aliyu, who has also been charged with him.

Eni and Shell are accused of handing out bribes during the 2011 purchase of OPL245, an offshore oil block, for $1.3bn.

READ | Ex-Nigeria minister held in Dubai over oil graft scandal: lawyer

Former oil minister Dan Etete is still on the run over the scandal.

It was during his time in office in 1998 that Malabu was illegally awarded control of the block.

Accusations against the international oil majors have led to a string of cases in a number of countries that have seen convictions in Italy and a probe against Shell in the Netherlands.