BP is beginning the fifth day of a subsea mission, under U.S. Coast Guard supervision, to search for possible oil leaks from the site of the Deepwater Horizon  disaster, according to reports. The oil rig explosion in 2010 killed 11 workers and leaked more than 7 million gallons of oil into the Gulf of Mexico over three months before it was finally capped.

However, a new oil sheen spotted in September about 50 miles off the Louisiana coast was confirmed as originating from the Macondo well underneath the Deepwater Horizon. An underwater vehicle from BP observed oil seeping from the containment dome over the well. After a remote operation, the leaks were declared plugged on Oct. 23, but the Coast Guard and BP said it wasn’t feasible to clean up the oil slick and that it didn’t pose any risk for the coastline.

Since that time, slicks and sheens of various sizes have shown up in satellite photos and aerial video, and the culprit is suspected to be oil seeping from the containment dome, wreckage and equipment from the 2010 disaster.

BP told CBS news in a statement that “the Macondo well and its associated relief wells are secure,” but that the company would continue to work with the Coast Guard on  “any further steps, as needed, to address the results” of this week’s survey of the wells and wreckage where oil still may be trapped.

The maritime attorneys at Schechter, Shaffer & Harris, L.L.P., Accident & Injury Lawyers represent workers injured in offshore drilling accidents, including the Deepwater Horizon explosion.