Energy giant BP said that seepage near its Gulf of Mexico well was unrelated to the massive oil leak that has at least temporarily been capped.

"Scientists have concluded that the seep was naturally occurring,” BP spokesman Mark Proegler was quoted as saying in a report in our sister newspaper, the Gulf Daily News.

Investors had feared that seepage could signal that the April 20 blowout that preceded the leak damaged the wellbore, which could allow oil and gas to leak out the sides and possibly breach the seabed.

Officials are monitoring the pressure in the well to gauge whether it is structurally sound. An intact well would help when a relief well intercepts and tries to plug the leak, but damage could complicate that effort.

Speculation also grew about assets the company may sell to pay multi-billion-dollar costs for its oil spill.

A top US spill official said that engineers had detected seepage, raising fears of problems with the cap that stopped oil from spewing into the water nearly three months after a rig explosion.

The company said that it had spent $3.95 billion to tackle the well and that it aimed to permanently kill it in the first half of August.

It said it continued to run an integrity test on the well, on which it placed a cap last week that appeared to seal the well and that pressure continued to rise.

BP choked off the flow 1.6 km under the water's surface with a cap on Thursday, marking the first time oil has not spewed since the April 20 explosion on an offshore rig killed 11 workers.

Analysts said investors were concerned about seepage reports. "There's been a lot of punting around the stock," Evolution Securities oil analyst Richard Griffith said, adding that would likely be continued volatility.

"The only thing that matters is the relief well. If it doesn't work, they will have a massive problem."

National Incident Commander Admiral Thad Allen said that he had written to BP stating there were several unanswered questions about the monitoring systems it committed to as a condition of the US extending the well integrity test.

He listed detection of a seep near the well and the possible observation of methane over it. He said he had authorised BP to continue integrity tests for another 24 hours. – TradeArabia News Service