A piece of Superman memorabilia signed by the late actor Christopher Reeve is being auctioned by a charity after being found "hiding in plain sight" at its office for more than 40 years.

The wooden commemorative key had been hanging on the wall of Age UK's Milton Keynes building, which had served as a production base for Superman IV: The Quest for Peace.

Scenes for the 1987 movie saw Reeve dangled above Milton Keynes Central Station in his superhero costume.

The charity hoped the online sale would raise enough money to fund "urgent repairs and improvements" to its building, ensuring it remained a "welcoming and accessible place".

The Superman memorabilia came into the charity's possession as a thank you gift from Cannon Films, which produced the film.

The key was signed by the late Gene Hackman who played the character Lex Luthor and the late Margot Kidder who played Lois Lane.

It was valued at £2,500, although the auction house, Goldin Auctions in the United States, believed it could fetch a higher price because of its "unusual provenance and connection to such an iconic Hollywood film and its stars", according to Mark McCarthy, a spokesperson for the charity.

"Our ultimate dream would be for a local Milton Keynes business or individual to purchase the key at auction and bring it back home," McCarthy said.

According to fan Jason Joiner, who runs the city's National Film and Sci-Fi Museum, about 18 minutes of the 90-minute film was shot in Milton Keynes.

Several other locations across Hertfordshire were also used.

"There is something rather wonderful about the idea that a gift left behind by Superman his fellow Hollywood stars all those years ago could now help us give something back to the people of Milton Keynes," McCarthy added.

Bidding for the item remains open.

Danny Fullbrook looks back at when Hollywood came to MK.

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