Lee's 'Dracula' cloak found in shop
The 85-year-old confirmed the authenticity of the costume, which was discovered by a member of staff at London firm Angels.
The shop's owners unknowingly hired it out to members of the public after it was sent back to their stockroom after filming finished.
The cloak worn by co-star Peter Cushing in his role as Dr Van Helsing was also discovered in the store on Shaftesbury Avenue.
An Angels spokesman said: "When the 1958 Dracula film was being made, it was considered to be just another potboiler. No one knew it would be a hit so the costumes were not seen as significant.
"The cape went back into stock and was hired out to other films, and eventually to the public - once, rather bizarrely, it was rented out for a children's nativity play. When it was discovered, the documentation and serial numbers were matched. Christopher Lee then verified it in person during a costume fitting for another film last month."
The cloak is thought to be worth up to £25,000.