Causton - or should that be Wallingford - is bracing itself to welcome an influx of Midsomer Murders fanatics next month.

Wallingford is the fictional town of Causton, the main setting in the crime drama series popularised by Det Chief Insp Tom Barnaby, played by former Bergerac star John Nettles.

And a trip to the South Oxfordshire market town is the first port of call for fans from all over the world at the Midsomer Murders convention being held on the weekend of June 20-22.

Despite filming taking place in several counties, Oxfordshire is the heartbeat of Midsomer Murders and many of the instantly-recognisable backdrops - like The Old Fisherman pub in Shabbington - were filmed in the county.

Fans will be welcomed at the Corn Exchange theatre in Market Place, Wallingford, which will open specially for the event.

The Corn Exchange features in many episodes of the television detective series as the fictional Causton Theatre.

It is owned by the Sinodun Players, many of whom have appeared as extras.

Midsomer Murders convention organiser Joan Street said: "This event has been organised by a group of dedicated fans who met via two independent websites. It should be absolutely unmissable."

The planned itinerary for the weekend has the fans in Wallingford having a trip up the Thames on the Friday, with a quiz in Lewknor Parish Hall in the evening.

Saturday sees them in Thame, a popular venue for many of the episodes and a trip through Oxfordshire and Buckinghamshire countryside looking at locations in Long Crendon, Haddenham, Warborough, Shillingford, Dorchester, Nettlebed and Watlington.

There will be a picnic at Aston Rowant nature reserve on the Saturday evening.

The final day will include a steam trip along the foothills of the Chilterns, courtesy of the Chinnor and Princes Risborough Railway Association, and the weekend ends with a dinner, probably at the Spread Eagle in Thame, where several episodes were filmed.

Organisers hope members of the cast will be able to join them for part of the Midsummer in Midsomer convention.

Profits from the weekend will go to the Shakespeare Hospice in Stratford-upon-Avon, whose president is Mr Nettles.