A Milan court is now considering corruption charges against the two companies, stated BBC.

Following the revelations made by a campaign group Global Witness, it has come to light that the planned development of the OPL 245 deal offshore Nigeria has potentially led to the country losing nearly $6bn – double its annual education and healthcare budget.

According to the commissioned report, the offshore development contract was altered in favour of energy companies and would amount to a loss of $5.86bn for Nigeria (estimated losses were calculated using oil price of $70 a barrel)

Reports indicate that officials in Eni and Shell knew the money being paid to develop this project would be used for bribes, although the companies have denied these claims. BBC stated that the former Nigerian oil minister Dan Etete was found guilty in a French court of money laundering.

While the report has been criticised by Eni for calculating it on the basis of ignoring the possibility of Nigeria reserving its right to revise the deal to claim a 50% share, a Global Witness campaigner said that Shell had constructed a deal that cut Nigeria out of their share of profit oil from the block.

Now there is building pressure to cancel the deal.

The oilfield in question – OPL 245 – is a lucrative deal for Eni and Shell for it contains nine billion barrels of oil. The two companies claim to paid exploration rights to the Nigerian government directly, and therefore, have done nothing wrong. Shell has issued a statement that since the matter is before the Milan Tribunal, they would not comment any further and would not interfere with this issue, which are under consideration for a trial process.

Eni too has denied any wrongdoing, stating that it questions the credibility of the analysis itself.