Film trucks outside the Ashmolean, which was closed yesterday for filming of the first episode of Inspector Lewis, starring Kevin Whately, and Lawrence Fox, inset A triple murder investigation in Oxford is to be led by a veteran detective who has helped solve more than 20 suspicious deaths in the city.

Robbie Lewis, who has been promoted to the rank of Inspector since the death of his colleague and mentor Inspector Morse, is set to return to our television screens early next year in the first episode of spin-off series Inspector Lewis.

Filming of the new detective show began in Oxford this weekend with scenes being shot in and near the Ashmolean Museum yesterday.

Chris Burt, producer, said: "The pilot went out last year and was watched by 11m people, making it ITV's top show.

"We are now filming three more films, this shoot today being the first of the three. We are due to finish shooting at the end of November and the programmes are then due to be shown next spring."

About 40 crew were involved in yesterday's shoot and another 20 people, most of them Oxford residents, were used as extras.

Crews working on the ITV drama will be filming at various locations around the city over the next three weeks.

The decision to resurrect the character came four years after Morse's on-screen death in The Remorseful Day, during which Lewis - played by Kevin Whately - took the lead in an investigation into a year-old murder as Morse's health deteriorated.

It was 20 years ago that Mr Whately first appeared alongside John Thaw, who played his boss Inspector Morse, in The Dead of Jericho.

In the new series family-man Lewis returns as a widower, living alone in Oxford, having just returned from working abroad for a number of years.

In the first episode, Lewis and his young partner Det Sgt Hathway's investigation of the deaths leads them to a group of former Oxford University students.

Colin Dexter, author and creator of Inspector Morse, visited the set yesterday.