Quote:But that did not prevent Pickard disclosing the company's reach into the Nigerian government when she met US ambassador Robin Renee Sanders, as recorded in a confidential memo from the US embassy in Abuja on 20 October 2009.

At the meeting, Pickard related how the company had obtained a letter showing that the Nigerian government had invited bids for oil concessions from China. She said the minister of state for petroleum resources, Odein Ajumogobia, had denied the letter had been sent but Shell knew similar correspondence had taken place with China and Russia.

The ambassador reported: "She said the GON [government of Nigeria] had forgotten that Shell had seconded people to all the relevant ministries and that Shell consequently had access to everything that was being done in those ministries."

Nigeria is Africa's leading oil producer and the eighth biggest exporter in the world, accounting for 8% of US oil imports. Although a recent UN report largely exonerated the company, critics accuse Shell, the biggest operator in the delta, and other companies, of causing widespread pollution and environmental damage in the region. Militant groups engaged in hostage-taking and sabotage have proliferated.