Builders have discovered a mystery structure under a town's former police station.

The site in Windmill Street, Gravesend, is set to be turned into a 72-room retirement home.

But work has now been delayed after contractors on-site unearthed a mystery building earlier this week.

Aerial pictures show the archaeological findings at the former police station.

Gravesend historian Christoph Bull believes the find could be the remains from former Victorian homes.

Steps shown in the photo are less of a mystery – they were created to help archaeologists access the site.

The plot has been vacant for more than a decade since the £30 million north Kent police headquarters opened in 2008.

Gravesham council says work on the retirement homes, being led by Churchill Retirement Ltd, has not been halted, but instead "factored in as part of the site remedial works".

It is expected a full archaeological excavation will take around two months.

Previously, Churchill Retirement described the site as "an eyesore" which detracts from the area, and said its proposal would provide "high-quality independent living accommodation, with a communal lounge and gardens".

It is hosting a competition to name the new development – and will surely be hoping "Flatty McFlatface" isn't a suggestion.

The company added: "The proposal has been sympathetically designed and will contribute positively to the character and appearance of the area."

A statement on Churchill's vision for the site, says it aims to "deliver a development that meets our customers’ needs and the local need for retirement apartments whilst also contributing to the character of Gravesend and making a positive contribution locally in terms of socio, economic and environmental benefits".