Oil has washed up at Victoria's 90 Mile Beach, adjacent to the oil and gas poduction precinct in the Bass Strait.

Oil has washed up at Victoria's 90 Mile Beach, adjacent to the oil and gas poduction precinct in the Bass Strait. Photo: Jessica Shapiro

Some of Australia's biggest oil and gas producers are investigating the integrity of their Bass Strait operations after crude oil washed up on the Victorian coast.

The oil was found in a beaded form on more than six kilometres of Victoria's 90 Mile Beach, and has prompted a clean-up that was described as ''extensive'' by the state's Department of Transport, Planning and Local Infrastructure.

The beach is adjacent to Australia's original oil and gas production precinct in Bass Strait, which is still being worked by joint-venture partners ExxonMobil and BHP Billiton, as well as other players such as Santos and Nexus.

ExxonMobil said it was not aware of any problems with its infrastructure, but confirmed that it ''has been and is continuing to investigate''.

Exxon had to temporarily shut down its Cobia rig in Bass Strait last year after a small oil leak occurred in September.

Despite no problems being found with Exxon's infrastructure over recent days, the company has supplied equipment and personnel to help clean up the beach.

Santos operates the Patricia-Baleen rig nearby, and was firm in its statement. ''We can confirm that the oil is not from our facilities,'' the company said.