Who is the mystery man in this picture?

Apparently stripped to the waist and a little on the portly side, the ghostly figure sitting in a chair in the attic of the Edward Jenner Museum in Berkeley has foxed the photographer who took it.

"I don't believe in ghosts," said Chris Sandys, a BBC Gloucestershire broadcast journalist. "But this is strange! As soon as I'd taken the panoramic photo, I reviewed the image on the camera, and straight away noticed this strange formation of light, shaped like a figure, through the doorway in the next room."

He has tried unsuccessfully to recreate the shot but the apparition has not appeared again.

Picture by Chris Sandys, BBC Gloucestershire

Jenner, who discovered the vaccine for smallpox, owned The Chantry from 1785 until he died in 1823. Since 1985 it has been a museum which tells the story of his remarkable life, and a discovery which saved millions of lives.

The picture was taken in the servants' quarters on Thursday, and the house has served as a vicarage and billeted soldiers in its time.

"There have always been stories of ghosts at the Edward Jenner Museum," said Sarah Parker, the museum's director. "We usually take them with a large pinch of salt."

Ironically the museum in Berkeley has just opened up its attic for the first time to create a brand new exhibition: Ghosts in the Attic: from Smallpox to MMR. "We are truly flabbergasted by the image," said Sarah. "We have graffiti from soldiers previously billeted in the attic rooms from the 19th-20th Century and perhaps this is one of them or even one of Jenner's servants. Who knows whether it is Jenner himself?"

Visitors can find out for themselves throughout the year with tours of the atmospheric attic at weekends. An evening Halloween tour of the attic is also planned.