Shell Petroleum Company has admitted for the first time that it used a third party to negotiate access to a vast oil field in Nigeria.
This comes after emails were published showing Shell negotiating the deals.
Shell and an Italian oil company paid $1.3bn to the Nigerian government for access to the field while Investigators claim $1.1bn was passed to a private firm.
Shell and the Italian firm, ENI, agreed a deal with the Nigerian government for the rights to exploit OPL 245, a prime oil block off the coast of the Niger Delta.
Spokesman for the oil firm said there had been wide consultations before signing the deal.