Oil covers the surface of the Gulf of Mexico on the vicinity of BP's Deepwater Horizon spill source
Oil covers the surface of the Gulf of Mexico on the vicinity of BP's Deepwater Horizon spill source where numerous boats are unsuccessfully trying to stop the leak and clean the ocean on June 17, 2010. REUTERS

One of BPs partners at the ill-fated Deepwater Horizon oil well has accused the beleaguered oil giant of "gross negligence", a charge BP has denied in a week when its CEO Tony Hayward faced the wrath of the US Congress.

Anadarko Petroleum is an oil and gas company that owns 25 per cent of Deepwater Horizon. The company not only accused BP of "gross negligence or wilful misconduct" and of being "reckless" before the spill but added that it was thinking of pursuing "contractual remedies" against BP.

BP has said it disagrees with Anadarko's views, saying that the US company was "refusing to accept responsibility for oil spill removal costs and damages", although they are contractually obliged to do so.BP accused of "gross negligence" by Deepwater Horizon partner

On Thursday BP CEO Tony Hayward appeared before the US Congress and while admitting that he was "deeply sorry" for the disaster he was still accused of "stonewalling" his interrogators due to the number of questions where he stated that he didn't know the answer.

Mr Hayward, when probed about whether BP was responsible for the disaster happening only answered that investigations were currently under way and only once they were completed would it be known if BP was responsible.

BP stands to take a considerable financial hit this year thanks to the oil spill, having already agreed to pay $20 billion in compensation to victims of the oil spill that has destroyed their livelihoods.

BP also needs to pay to stem the flow of oil. Currently BP have been able to install a device which captures around 25,000 barrels of oil each day, but it is estimated that the leak is churning out 35,000 to 60,000 barrels per day.

Yesterday saw ratings agency Moody's downgrade BP's credit rating by three notches to A2, following downgrades by two other agencies earlier this week.