The allegations are understood to be linked to a relationship between Roger Brown, the adviser, and representatives in Colombia of an Israeli security firm, Silver Shadow.
BP is a majority shareholder in the Ocensa pipeline, which is regarded as a military target by left-wing guerrillas.
The company relies on the Colombian army to protect the pipeline and its personnel. Responding to reports that Ocensa supplied military equipment to one brigade, a spokesman for BP said last night that the only thing that had been provided was night-vision equipment.
But the question of arming the brigade with attack helicopters and guns had been under discussion at one time, the spokesman, Roddy Kennedy, said.
Mr Kennedy said that while the recently completed pipeline was being built, Mr Brown had proposed a number of options for improving security, most of which had been rejected by the Ocensa management.
He said that Mr Brown was suspended two weeks ago, adding: "Our investigations have offered no evidence that he did anything wrong."
Mr Kennedy said: "The pipeline runs through extremely dangerous and isolated territory, an area that has been fought over for decades."Reuse content