HALIFAX - BP Canada has reported a spill of drilling fluids from its oil exploration operation taking place off the coast of Nova Scotia.

An incident report on the Canada-Nova Scotia Offshore Petroleum Board website said there is a “preliminary estimate” that 136 cubic metres spilled from the West Aquarius drilling unit on Friday before it was stopped.

The news release said an early investigation by the company indicates the spill occurred in piping about 30 metres below sea level.

Anita Perry, regional manager of the energy giant, said her company, “takes this incident very seriously and will continue with the investigation to understand the cause.”

The regulator said the exploration well is secure and drilling has been suspended while the cause of the leak is investigated.

Synthetic-based mud is a heavy, dense fluid used during drilling to lubricate the drill pipe and regulate reservoir pressure.

The West Aquarius is currently located approximately 330 kilometres southeast of Halifax.

The release said drilling will not resume until BP Canada receives approval from the CNSOPB that it may proceed.

A spokeswoman for the regulator declined to provide a board expert on spills for further comment, saying the board will not comment while the inquiry is ongoing.

The province's offshore regulator granted BP Canada Energy Group approval to begin drilling off the province's southeast coast in April.

The Aspy D-11 exploration well is the first of what could be as many as seven exploration wells over a three-year period.

That decision has raised the ire of several environmental and conservation groups that have raised concerns about the risk of a spill.

In addition, the Council of Canadians has said the government needs to move away from fossil fuels and invest in sustainable energy.

“Today marks only two months since BP started drilling, and already there has been a significant spill,” Angela Giles, Council of Canadians' Atlantic regional organizer, said in a statement.

“This is an example of what can happen when our governments let irresponsible companies do irresponsible projects that threaten our environment and economy.”