Oil from the Gulf of Mexico spill has crept further into the Mississippi Delta.

Sticky brown and orange globs and sheets have been spotted on grass and reeds in Louisiana's wetlands.

Environmentalists have feared that the marshland would be hit ever since the explosion in the Gulf. The area is home to a rich variety of marine life as well as rare birds and mammals.

Anger has been mounting over efforts to contain the spill. A video of large amounts oil still gushing into the water has been posted online after lawmakers exerted pressure on BP.

At least 6 million gallons have spurted into the sea in the time since the explosion with a large number of scientists claiming the figure is much higher.

A mile long tube has been inserted into the leeking pipe and officials say it is capturing 210-thousand gallons of oil a day but some is still escaping.

Doug Suttles, the BP executive in charge of fighting the leak, has said that he understands public frustration but oil could continue to spill out until August, when a new well will have been drilled.