Professor Trevor Kirkham was also told how the Prince of Wales apparently took an interest in paranormal events at Chingle Hall, at Goosnargh, near Preston, Lancashire, the High Court in Liverpool was told.
Revelations of strange goings-on at the 13th-century moated manor house were made by the then owner, John Bruce, a barrister, at a two- hour meeting in 1988, Professor Kirkham, of Montreal University in Canada, told the court. He and his wife Judy are claiming pounds 120,000 damages from Mr Bruce and the solicitors who handled the sale for misrepresentation. The couple say they were misled over profits and income from the house and the availability of planning permission for the Grade II listed building before they bought the property.
Chingle Hall - the oldest brick-built domestic building in England - is mentioned in many reference books, which call it 'the most haunted house in Britain'.
The court was told how Mr Bruce bought the house in 1986 but fell behind in his mortgage payments. There was a repossession order on the house.
Professor Kirkham, who was originally from Preston, Lancashire, and emigrated to Canada in 1973, said: 'John also told us he had written to Prince Charles and had a letter back from him which he would show us later - although we never saw it.'
The Kirkhams' counsel had described the couple as 'gullible and naive' for buying the hall for pounds 420,000 when it was worth about pounds 235,000.
Their 'fantastic dream' collapsed when planning authorities turned down their plans to make the hall a tourist attraction.
The case continues today.