'Unforgotton' will return for for a fourth series with Nicola Walker and Sanjeev Bhaskar back in the fold.

Nicola Walker

Nicola Walker

ITV has announced that the popular drama will see the pair return as DCI Cassie Stuart and DI Sunny Khan to tackle "another emotionally charged and compelling cold case".

The upcoming six part series will be written by creator Chris Lang and directed by Andy Wilson, as the pair keep up their collaboration after working together on the prevous three seasons.

Chris said: "I am so delighted to have been asked to make a fourth series of Unforgotten. The reaction to series 3 was better than I could ever have expected (with more people watching the last episode than any other in all three series) and I cannot wait to discover what lies ahead for Cassie and Sunny, and to create a whole new cast of characters for them to grapple with."

The third series aired on ITV earlier this year, with the finale getting an average audience of 6.9 million as it proved a huge hit with both viewers and critics.

Now, the channel's team is looking forward to what the future will hold for the police drama.

ITV's Head of Drama Polly Hill added: "We have been delighted with the reception of the first three series of 'Unforgotten' and are thrilled to commission a fourth instalment.

"Chris Lang's writing is incredibly powerful and his storytelling utterly compelling, so we have no doubt that the new case will have viewers gripped again."

Meanwhile, the programme's executive producers revealed they were delighted with the way it's grown in popularity.

Laura Mackie and Sally Haynes said: "Unforgotten has gone from strength to strength and we were so pleased to see the audience grow for the third series."