BP Plc could be spending as much as $10 million a day on clean-up efforts after a giant oil spill in the Gulf of Mexico, exceeding initial estimates, the Sunday Telegraph quoted Chief Executive Tony Hayward as saying.

Deepwater Horizon, a drilling rig contracted to drill a well for BP exploded and caught fire last month, causing a massive leak. The well is still pumping oil into the Gulf, generating a slick which is threatening wildlife, fishing and tourism.

Hayward was quoted as saying it could still be weeks or months before the leak is brought under control.

BP has not put an estimate on the cost of the spill, but the company said last month it and partners in the well were paying $6 million a day in clean-up efforts. It admitted at the time that costs would rise sharply when the oil hit land.

Hayward, quoted by the paper as saying he had ordered a complete safety overhaul of all BP rigs, said he now expected regulators to put in a series of new safety measures.

It is clearly necessary for the industry and regulators here to step back and take stock of this when we understand fully what has occurred and then determine what are the right additional safeguards that need to be applied, Hayward told the paper. There clearly are many.

(Reporting by Clara Ferreira-Marques; Editing by Erica Billingham)