BP shares, which have been rallying over the past three weeks, slipped 2.6 percent after the top U.S. government spill official said that engineers had detected seepage, raising fears of problems with the cap that stopped oil spewing into the water nearly three months after a rig explosion.

A BP spokesman said the seep was detected by its engineers but it was unclear whether the source was the blown-out well, adding that seeps were a natural phenomenon in the Gulf.

BP (BP.N) finally choked off the leak on Thursday, the first time it has managed to cap the flow since the blowout on April 20 which has caused the worst offshore oil spill in U.S. history and an environmental disaster for the U.S. Gulf coast region.

Investors welcomed the news that the leak has been capped but remained cautious since BP needs to complete 48 hours of tests on whether the well will remain intact after a new tight-sealing containment cap was installed on the mile-deep subsea wellhead three days earlier.

The group, which is in lawmakers’ crosshairs over the largest offshore oil spill in U.S. history, also confirmed on Thursday that it had lobbied the UK government over a prisoner transfer agreement with Libya in late 2007. In August 2009, the UK released a Libyan convicted of blowing up a U.S. jet, provoking an angry American reaction.

The spill started after an explosion at a rig on April 20 ruptured an undersea well and killed 11 workers, and has soiled hundreds of miles of shoreline and shut down about a third of Gulf fisheries.

“It’s too late for me now,” she said, fighting back tears at the Freestore Foodbank in the low-income Over-the-Rhine district near downtown Cincinnati. “But it will be terrible for the people who’ll lose their benefits if Congress does nothing.”

For nearly two years, Coleman says she has filed an average of 30 job applications a day, but remains jobless.

The results of the Washington Post/ABC News poll are a reversal of what voters said at the start of Obama’s presidency 18 months ago when about 60 percent expressed confidence in his decision making.

Confidence in Obama is at a new low but the poll found that his numbers are still higher than lawmakers of either major party four months ahead of the November congressional elections.