An auctioneer inadvertently triggered a full-scale police alert when he unearthed a hand grenade in a garden shed.

Charles Hanson, of Hansons Auctioneers in Lichfield, had been instructed to clear the home of Mary Craddock in Lichfield Road, Brownhills, following her death earlier this year at the age of 94.

Mrs Craddock had shared the home with her sister Ann Seedhouse until she died four years ago aged 92.

As he was rifling through an old chest of tools in the garden shed, Mr Hanson spied the grenade – thought to date back to the First World War – nestling in the corner.

“I’ve found some things in my time but this was a real shock,” Mr Hanson said.

“When you inspect a property which has been lived in by two ladies in their 90s you certainly don’t expect to find a grenade in the shed.”

Mr Hanson and his haulier David Booth quickly contacted Staffordshire Police who carried out a detailed inspection to confirm that the grenade was not live. “The chest hadn’t been touched in years, and you can’t be too careful,” the auctioneer said.

“It turned out it had been repinned and was obviously kept as some kind of memento.”

Mr Hanson said he couldn’t be sure whether the sisters were aware of the grenade lurking in their garden shed. “Our client acting on behalf of the estate certainly had no idea,” he said. The grenade will be auctioned along with the rest of the contents of the sisters’ home on Wednesday at the Old Mackworth Hotel in Derbyshire.

The siblings, who were both avid antique collectors, lived out their twilight years together in the Lichfield Road home – known as Maybury – which was purchased by their father in the 1920s.

Collectively, the contents of the house, which included a rare pair of drug jars kept from Miss Seedhouse’s years as a pharmacist in Brownhills, are expected to fetch between £20,000 and £25,000.

Mr Hanson said: “I’ve been into many homes in my career but this one really seemed completely untouched. It was a delight to see so many fine antiques dotted around.”