Unforgotten season 4 begins filming again - and Sunny's backpack is returning too

Meanwhile star Sanjeev Bhaskar also posted on Twitter, and it looks like Sunny's much-loved backpack will be making a return too. Alongside a picture of him holding up the bag, he tweeted: "Transformation complete. Let’s go to work."

The show, created and written by Chris Lang, follows Cassie and Sunny as they attempt to solve a series of murder cases that have remained unsolved for many years.

Filming on series four had previously begun in January of this year, before production was shut down in mid-March as the coronavirus began to spread rapidly throughout the country.

It remains to be seen how those two months of original footage will be blended with new footage as the shoot progresses, but intriguingly the clapperboard suggests that the day's filming began with episode one, scene one.

Season four will begin with the discovery of a dismembered body in a scrap metal yard. The body belongs to Millwall Football Club supporter Matthew Walsh, and the detectives believe it may have previously been stored in a domestic freezer for 30 years.

Considering he had gone missing in the ’90s and the owner of the freezer is dead, the mystery behind Walsh’s death will be a hard one to unravel.

For her part, Cassie will find herself making the "gut-wrenching decision to return to work", despite her decision to retire from the police force for “her own sanity and wellbeing.”

In addition to Walker and Bhaskar, the cast for series four – as previously announced by ITV before lockdown – also includes Sheila Hancock, Susan Lynch, Phaldut Sharma, Liz White, Andy Nyman, Clare Calbraith and Lucy Speed.

The wait for series four has been a long one for fans of the show, with more than two years having already passed since the third series finished in August 2018 - and it's still unclear when in 2021 we can expect to see the next run.

Unforgotten will return in 2021. Looking for something else to watch? Check out our TV Guide.