Italian investigators have arrested 15 people, including Piero Amara, a popular lawyer in the country, and Giancarlo Longo, a magistrate, in connection with the Malabu scandal.
Among those arrested were professionals, consultants, professors who were accused of trying to cover up issues relating to the bribes allegedly paid in Nigeria.
“They had put up a fake investigation to pollute the Milanese on Descalzi and the bribes in Nigeria,” Repubblica, an Italian newspaper, reported on Tuesday.
The arrests were carried out between Rome, capital of Italy, and Messina, the third-largest city on the island of Sicily.
The Malabu deal involved OPL 245, an oil block considered to be the richest in Africa.
An estimate says OPL 245 holds reserves of 9.3bn barrels of crude oil and gas reserves.
In the deal finally consummated in 2011, only $210 million of the $1.3 billion paid by Shell and Eni for the block went into federal government coffers as “signature bonus”.
The rest was paid to Malabu Oil and Gas, mainly owned by Dan Etete, who, as petroleum minister in 1998, had awarded the lucrative licence to himself.
The sale to Malabu was nullified by former President Obasanjo in 1999 and assigned to Shell — without a public bid.
Ownership was suspiciously reverted to Malabu thereafter, leading to legal action by Shell who later resorted to negotiating directly with Etete after President Goodluck Jonathan assumed office in 2010.
A year later, the $1.3 billion deal was struck, with Malabu getting $1.1 billion from Shell and Eni to its transfer ownership, while the signature bonus was paid to Nigeria.
Italian detectives had said some of its citizens paid bribe to Nigerian officials involved in the deal.
Court documents filed in in Milan, an Italian city, in December 2016, outlined a case against 11 people, including senior executives from Eni and Shell as well as the companies themselves.
Claudio Descalzi, ENI chief executive and his predecessor Paolo Scaroni, were said to have met with Jonathan to sort out the deal “in person”.
The prosecutors alleged that ENI and Shell executives worked with Etete during the military administration of Sani Abacha.
$801.5 million was allegedly transferred to Etete’s Malabu accounts while $54 million was said to have been withdrawn by Abubakar Aliyu, who was described as an “agent” of Jonathan.
The prosecutors added that beneficiaries of the money went on a shopping spree buying “property, aeroplanes, armoured cars”.
Jonathan had denied the allegation.