Yenagoa - Nigeria has arrested two Britons and 10 of its own citizens on charges of trying to bribe a military officer to facilitate oil theft, the military said on Friday.
Oil theft by armed gangs is rampant in Africa's top crude-producing country, with estimates ranging from 100 000 barrels to 250 000 barrels a day lost to so-called "bunkerers".
Major-General EJ Atewe, commander of the mixed military and police Joint Task Force (JTF) for the oil-producing Niger Delta region, said two of the bunkerers, both Nigerian, had gone to an officer to request clearance to move the crude oil.
They had openly admitted their plan was to hack into a pipeline and connect a hose that would siphon crude out of it onto a waiting boat, and offered him $6 500 to provide a gunboat to protect them on the way out.
"The suspects were immediately arrested for attempting to bribe the brigade commander for economic sabotage," Atewe said in a statement, and a follow-up operation had led to the arrest of two Britons and another eight Nigerians.
Stories of collusion with the security forces are common and the sheer scale of oil theft in Nigeria would not be possible without systematic collusion by various security agencies, security sources say.
Loss of output from theft and outages caused by sabotaging pipelines has cost the treasury - which relies on oil for about 80% of revenues - billions of dollars. Critics, however, say theft is exaggerated to cover up embezzlement of oil revenues by officials in the state oil firm, a charge they deny.
Oil theft has contributed to the high likelihood Nigeria will lose its top African crude oil exporter spot in May, as exports could fall to their lowest since records began in 2009.
Production of the Forcados grade has been hit by underwater pipeline leakage, which Shell blamed on oil theft, and which led the operator to declare force majeure on the grade this week.
Despite widespread evidence of collusion between Nigerian security forces, the government has been keen to portray oil theft as the work of foreign criminal gangs. Analysts say the main buyers are gangs in the Balkans and refiners in Singapore.