A Portland company boss who endangered troops and cheated the Ministry of Defence by selling it equipment unfit for purpose in a £1.4 million planned fraud has been jailed for three years and four months.

Carl Tiltman, 56, duped the Royal Navy into investing in underwater scanning technology after using fake test results to lie about its capabilities in his sales pitch.

Navy personnel were put at risk by carrying out "completely futile" live training operations to test the laser-emitting kit which "produced no meaningful results whatsoever", Southwark Crown Court heard.

Tiltman had persuaded his former employers the MoD to place orders for specialist sonar imaging devices and safety equipment worth around £1.4 million while chief executive of Subsea Asset Location Technologies (Salt). The firm had been based at Osprey Quay, Portland and has since entered liquidation.

He appeared in court wearing a red fleece jacket and cargo trousers as he was sentenced yesterday.

Judge Christopher Hehir told him: "Your offending was clearly very serious indeed and in breach of a very high degree of trust reposed in you by both your company and service personnel.

"The offending was protracted in time and caused or contributed to very substantial financial loss and damage... as well as causing some risk to the life and limb of service personnel.

"I'm entirely satisfied you caused a loss of half a million pounds of actual financial losses. It is likely that the losses you actually caused were far higher than that."

Tiltman, of Hawkchurch, Devon, admitted fraud by false representation and fraud by abuse of position in November.

Prosecutor John Greany said: "The deception started in earnest in May 2017 and at that stage Mr Tiltman gave formal presentations about making specific claims about what the scanning equipment could achieve.

"Results... had been fabricated by Mr Tiltman.

"Not all of the roughly £1.4 million that might have been lost was in fact lost.

"Over £800,000 was mostly wasted... the actual loss was over £500,000."

The figures do not account for the "substantial and additional" staffing, training, and operational costs, Mr Greany said, adding that the MoD had also suffered reputational damage and embarrassment.

The main technology was called LIDAR (Light Detection and Ranging), which uses lasers to detect and scan items like ships and underwater pipelines to produce images for analysis.

Tiltman had used the "rough" pictures produced "as the basis for his own, more detailed fabrication" to dupe officials, Mr Greany said.

But it exposed service personnel to unnecessary risk after they trained for up to eight months to carry out live training exercises with the heavy machinery which emitted lasers potentially harmful to eyesight, the court heard.

In one case, Tiltman persuaded someone identified only as Soldier A he had fitted a remote control system to the scanner.

"But Soldier A realised it did not have that remote capability and had to go back into the water to turn it on and off", the prosecutor said.

It also appeared that Tiltman sabotaged the battery of the device so his fraud would not be uncovered, Mr Greany told the court.

The deception unravelled in January 2018 after the MoD was warned by a third party.

The fraud by abuse of position charge relates to lies told by Tiltman to his company Salt about a blackbox-like aviation technology called SkyBell used to help locate wreckages.

Tiltman admitted deceiving investors and directors of Salt by fabricating ongoing high interest from companies like Airbus months after discussions about buying the technology had ended.

He was sentenced to two years for that charge and three years and four months for the fraud by false representation charge, to be served concurrently.

Tiltman, who is of previous good character, worked for the MoD in a civilian capacity in the 1980s.