Oil prices dropped on Friday amidst oversupply concerns and are expected to end the week more than 5% lower.

Brent crude futures were trading 25 cents lower at $49.27, while US crude futures were trading flat at $44.66 a barrel, Reuters reported.

Prices were under pressure as a very large crude carrier (VLCC), Sea King transporting two million barrels of North Sea oil was turned back from South Korea.

"We’re back down to the levels where we had a strong negative impact on drilling activity in the US."

Petromatrix oil analyst Olivier Jakob told Reuters: "The Sea King is part of the reason Brent is sinking.

"This is not a usual move and does not bode well for North Sea crude oil that has been relying on shipments to Asia to clear the overhang that was visible during June."

The oil trading company Vitol is now reoffering the Sea King crude, which has set off from the UK two weeks ago.

Investors are keenly awaiting US jobs data to be released later on Friday. The data is expected to give a strong pointer in the near term on when the Federal Reserve will increase interest rates for the first time in nearly ten years.

Jakob told the news agency: "We’re back down to the levels where we had a strong negative impact on drilling activity in the US."