Dutch prosecutors are preparing criminal charges against Royal Dutch Shell over its $1.3 billion acquisition of Nigerian offshore oilfield OPL 245 in 2011.

Shell said in a statement on its website that it had been informed by the Dutch Public Prosecutor’s Office (DPP) that it had nearly concluded its investigation and is preparing to prosecute Shell for criminal charges directly or indirectly related to the 2011 settlement of disputes over OPL 245.

The Dutch decision piles pressure on Anglo-Dutch oil major Shell, which is already facing charges of bribery in a trial in Milan over the same deal alongside Italy’s Eni.

Prosecutors in Italy allege that the two oil companies knew that around $1.1 billion used for the acquisition of OPL 245 would be used to pay politicians, businessmen and middlemen.

Both oil firms have denied any wrongdoing.

A spokeswoman for the Dutch prosecutors said: “Based on the preliminary criminal investigation, public prosecutors concluded that there are prosecutable offences”.

Under the deal, Eni and Shell jointly acquired the OPL 245 field from a company owned by former Nigerian oil minister Dan Etete, who was convicted of money laundering in an unrelated case in France in 2007.

Eni Chief Executive Claudio Descalzi and four ex-Shell managers, including its former head of upstream, Malcolm Brinded, are also facing charges of international corruption in the Milan trial. All have denied any wrongdoing.

Shell shares were up 0.37 percent at 0923 GMT.

It was not clear whether the Dutch prosecutors will be relying on materials in a suitcase seized nearly three years ago by Swiss authorities from Emeka Obi, who was convicted by an Italian court over the Malabu oil bribes.

The suitcase was unsealed two months ago and the contents were believed to have the potential to shed light on the recipients of the $1.2billion bribe.

Among the documents in the suitcase were an external hard drive, British and African passports, and USB keys. (NAN)