A DETECTIVE drama has transformed a water works into a secret laboratory for an upcoming episode.

Popular BBC One drama Inspector George Gently has been filming at Mosswood water treatment works near Consett, County Durham for an episode to be broadcast on Thursday, February 20.

The site will form the backdrop for a secret drugs laboratory known as ‘Hopewood’ in the third episode of the current series.

Actors Martin Shaw, who plays the title role and Lee Ingleby, who plays Detective Sergeant Bacchus filmed the scenes back in June 2013, with a full supporting cast and a 30-strong film crew.

The treatment works remained fully functional during the filming and was chosen as a perfect fit for the drama’s 1969 setting as it still retains most of its original 1960s features.

The site, which is owned by Northumbrian Water, supplies drinking water to South Tyneside, Washington and part of Sunderland.

David Pattinson, team leader at Mosswood, said: "We were really excited to be used as a location for Inspector George Gently. It’s not every day that your place of work is used for a top TV drama series. We’re keeping the ending a secret but we can’t wait to see the finished result on screen."

Northumbrian Water’s Waskerley Reservoir was also used as the backdrop for the same episode.

The location fee was donated to the charity Wateraid, which provides safe drinking water to some of the world’s poorest communities.