ConocoPhillips, the operator of two leaking oil platforms in Northeast China's Bohai Bay, said they had discovered more oil-based mud on the seabed around Platform C which may push the total leak to surpass 1,500 barrels.

The news comes just a day after the State Oceanic Administration blasted the company for failing to stop the leak and clean up the contamination quickly enough.

ConocoPhillips said it has yet to conclude how much oil has leaked. "We're hoping to get the amount in the next day or two," the company spokesman John McLemore said.

He said the new discovery will cause more oil sheen to be seen on the surface, and may affect its cleanup process to meet the deadlines set by the State Oceanic Administration.

McLemore added, "We're striving to meet the deadline, but it will depend on the sea current and weather conditions. We don't want to put our divers at risk".

Divers discovered the oily mud, which was not easy to spot due to the muddy water on the seabed.

The oil spill was first discovered on June 4 around Platform B, and a new leak around Platform C was spotted on June 17.