The British Department of Energy and Climate Change reported sheen was observed near the Tartan Alpha platform, operated by Talisman Energy. The DECC said aerial observations suggested the sheen represented as much as 250 barrels of oil.
The department said there was nothing to suggest a release was ongoing. Talisman confirmed that a minor leak occurred in a subsea pipeline connected to the platform.
Talisman told the BBC a crack was discovered on the pipeline connected to the Galley oil field in the North Sea.
"We take our responsibility to safeguard the environment very seriously and, as a precaution we deployed a spill recovery and containment vessel with oil spill response equipment on board, while monitoring the leak area by (remotely operated vehicle) on a round-the-clock basis," the company said.
Oil leaked from the Gannet platform, operated by Shell, in the North Sea in August 2011. The release totaled around 1,300 barrels of oil, making it the largest oil spill in the region in more than a decade.