Shell has filed a criminal complaint in the Netherlands against a former employee in connection with a 2011 oil deal in Nigeria, a company spokesperson said on Wednesday. News of the complaint, which was filed last week, comes at the same time the energy giant is facing a criminal trial in Italy over an allegedly corrupt scheme to acquire a Nigerian oil block called OPL 245.Though the complaint is not connected to the billion dollar OPL 245 deal, the employee was working for Shell when both deals took place. "Based on what we know now from an internal investigation, we suspect a crime may have been committed by our former employee...against Shell in relation to the sale process for Oil Mining Lease (OML) 42 in Nigeria in 2011," said a Shell spokesperson in an emailed statement."We have filed a criminal complaint with the Dutch authorities and are considering other steps we could take."KEEP UPDATED on the latest news from around the continent by subscribing to our FREE newsletter, Hello Africa.FOLLOW News24 Africa on Twitter and Facebook. The spokesperson said that the two deals are "unrelated" and that there is "no case against Shell or its former employees" in the OPL 245 case. The employee may have recieved kickbacks through a company listed in Seychelles during the "unusual" sale of OML 42 to Nigeria's Neconde Energy in 2011, said a company source.Anti-corruption campaigners welcomed the news as a promising development. "After years of saying that there is no place for bribery or corruption in their company, they have finally admitted that one of their most senior executives may have taken kickbacks in return for an oil deal," said Barnaby Pace of Global Witness, an international non-governmental organisation.Corruption is rife in Nigeria, one of Africa's biggest economies, but perpetrators elude prosecution, often relying on an elaborate web of shell companies and middlemen to avoid detection and obfuscate blame.