The Hatton Garden burglars may have worn metallic cloaks to avoid detection by infrared sensors during an earlier raid on a Bond Street jewellery store, a court has heard.

Michael Seed, 58, is alleged to be the alarm expert nicknamed “Basil” who was involved in both the £13.7m Hatton Garden heist in 2015 and the £1m Chatila burglary five years earlier.

Woolwich crown court heard that one of the thieves may have posed as a BT engineer before tampering with the jewellers’ security system prior to the raid in 2010.

One theory put to jurors is that burglars cut the phone line to the alarm and used a 2G blocker to jam the mobile signal and prevent it communicating with the outside world.

An electrical engineer, Gordon Herrald, said in a report that movements detected by infrared sensors indicated that someone had hidden in the alarm cupboard or under a table in the shop’s viewing room for 26 hours.

But giving evidence on Monday, he told the jury he did not think this was practical and suggested another theory.

“Another one is they came through the wall, they got past the detectors, coming up the stairs, by cloaks – metal suits or whatever – then got to the alarm panel to do the work,” he said.

Seed, from Islington, north London, denies two charges of conspiracy to commit burglary over the Hatton Garden and Chatila raids and one charge of conspiracy to convert or transfer criminal property.

Brian Reader, 79, John “Kenny” Collins, 78, Daniel Jones, 63, Carl Wood, 61, and Terry Perkins, who died last year aged 69, have been convicted of conspiring to carry out the burglary, while William Lincoln, 63, Hugh Doyle, 51, Terri Robinson, 38, and Bren Walters, 47, were also convicted in connection with the crime.

Jones pleaded guilty to the Chatila burglary, while Perkins died in prison before he could be tried. Charles Matthews, 55, was convicted earlier this year of receiving stolen goods from Chatila.

The trial continues.