The Coast Guard says a series of "sheen sightings" have been reported in the area where the Deepwater Horizon drilling rig exploded in the Gulf of Mexico last year, but BP's capped well isn't the suspected source.
A statement issued Tuesday by the Coast Guard says the sheens could have come from the sunken rig's riser pipe or from other underwater debris. The Coast Guard says recent video footage shows no evidence of a leak from the blown-out well that was capped last year.
Authorities haven't determined whether the sheens could be from oil, diesel or another substance.
The Coast Guard has notified rig owner Transocean Ltd. that the company may be financially responsible for any cleanup costs if the sheens are coming from the rig's wreckage.