York is Europe's most haunted city, according to a world authority on psychic phenomena.

Parapsychologist, Jason Karl, president of the Ghost Research Foundation International, said York has more ghosts than any other city not just in the UK but across Europe.

The organisation, known as GRFI, was founded by Mr Karl nearly 10 years ago and aims to research alleged ghostly phenomena worldwide.

"We have travelled extensively working on research projects across the globe and nowhere have we found more ghosts than in York," he said.

The revelation is no shock to residents of York, who know a lot of tales about ghost sightings and who live or work in many of the old listed buildings, which the spirits are said to haunt.

The city, which has four million visitors each year, holds regular ghost walks which can attract nearly 150 tourists at a time.

One of the most famous spiritual visitors in York is the Grey lady, who is said to haunt the room behind the dress circle of the Georgian Theatre Royal.

She is regarded as a good omen to any performers who see her. The Grey lady was a nun who was bricked into the walls as a punishment for becoming the lover of a nobleman.

To mark its paranormal status, York will be hosting GRFI's 10th anniversary celebrations on September 6 and 7. Members of the public will be able to take part in real ghost investigations run by psychic investigators and scientists.