Thieves stole metal worth £30k from a historical landmark being revamped into a property developer’s holiday let.

Suspects made off with a large steel supply from Gary Mayatt’s Martello Tower No. 25 in Dymchurch prompting a police investigation.

Mr Mayatt recently unveiled plans to revamp the former fort, dating back to the Napoleonic Wars, by the year’s end as a project of passion.

But now thieves have stolen and vandalised part of the roof he is concerned the finishing date will be significantly pushed back.

Mr Mayatt, director of Dartford-based Enevate Homes, said: “Work had been progressing well inside the tower, and we were actually ahead of schedule.

“But the steel being removed from the roof is a major setback.

“Over £30,000 of material was taken, and it will put the project back a few months, maybe even more.”

Mr Mayatt impulsively bought the fort in May, after it appeared on the market, reminding him of his childhood holidays in the area.

The incident was reported to police last Wednesday, and enquiries remain ongoing.

Located in the Dymchurch Beach car park, the tower was built between 1805 and 1809 and offers views over the English Channel.

The granted plans for the holiday let, which Folkestone and Hythe District Council approved, include dividing the tower into four storeys connected with a new spiral staircase.

An original scheme put forward by Dealtry Investments never got off the ground but Mr Mayatt told KentOnline at the time he hoped to bring the site back to life.

According to planning documents, the ground floor will consist of a lobby, storage, and a cinema room to use the lack of natural lighting.

However, the existing stairwell will be retained for occasional access to the top level.

A skylight at the top of the new staircase will provide natural light for the whole building. Four double bedrooms, each with its own en suite, are located across the first and second floors.

Two new windows are also due to be installed on the second floor.

The third-floor plans feature an open-plan kitchen, diner, and a small external terrace "providing undisturbed views out to sea".

External alterations include added glazed panels and window openings and provision for three on-site parking spaces.

The tower is one of 27 Martellos built along the Kent coast - and 74 in total along the south coast - to protect the British Empire from overseas invasions.

The forts, each about 40 feet tall, were designed to hold 15 to 25 men.

Officers were also called to the Grand Parade, Littlestone, further down the coastline, where beach huts had been broken into overnight.

Two teenagers have since been arrested on suspicion of burglary, with residents furious at being left to pay for the damage caused.

It has since been confirmed that the incidents are not being treated as linked.

Officers are now appealing for information in a bid to assist their investigation into the theft at the Martello Tower.

In a statement, a spokesperson said: “It was reported to Kent Police at 12.19 pm on Wednesday, September 4, that damage had occurred to the roof of a Martello Tower on Dymchurch Road, Dymchurch, and that part of the roof was missing.

“Enquiries are ongoing; anyone with information can contact Kent Police quoting 04-0546.”