Pilots trained in top-secret military operations are understood to be scouring lochs and forests in the search for murdered Emma Faulds’s body.

Flight-tracking software detected a private plane apparently carrying out surveillance above lochs in rural Ayrshire – the area police say holds the key to finding the 39-year-old’s remains.

Emma, from Kilmarnock, was last seen on April 28 in the Monkton area, about 40 miles away from the search site.

Police believe she has been murdered but her body has not been found.

Ross Willox, 39, was charged in connection with her death earlier this month.

A twin-engined Piper PA-31 Navajo aircraft from the south of England was spotted over the B7027 between Barrhill and Newton Stewart.

A twin-engined Piper PA-31 Navajo aircraft from the south of England was spotted over the B7027 between Barrhill and Newton Stewart

It appeared to focus on several areas of water, including the Maberry and Ochiltree lochs.

Operated by Northampton-based 2 Excel Aviation – a private firm reported to provide surveillance planes for the military – the aircraft covered more than 20 miles of terrain last week.

In 2016, it was reported that 2 Excel and its roster of more than 30 ex-military pilots had trained several British Army brigades deployed in Afghanistan on how to work with drones and combat jets during operations.

A source said the aircraft was sent in after a police chopper surveyed the vast site and mapped out spots of significance.

Flight-tracking software detected the plane apparently carrying out surveillance above lochs and fields in rural Ayrshire and Galloway

They added: “The aircraft was spotted flying a search pattern near Barrhill and also searching further south as far as Knowe village, just north of Newton Stewart.”

The exercise is similar to that believed to have been used in the search for murdered Suzanne Pilley, from Edinburgh, who is thought to have been buried in an Argyll forest almost a decade ago.

Her remains have never been found.

Thermal imaging equipment is understood to have been used in both cases to focus on areas where disturbed ground is identified.

Police searching for Emma are also understood to be focusing on another area of significance, Kilgallioch wind farm, just west of the plane’s flight path.

Emma Faulds has not been seen since April 28 in Fairfield Park, Monkton, South Ayrshire

Emma, who had worked with Paisley children’s charity Kibble for 12 years, is believed to have previously worked as a police officer and a prison custody officer.

Searches were carried out around her flat on Kilmarnock’s Fullarton Street, where she lived with her West Highland terrier Maverick, and at another property in Ayrshire earlier this month.

Last week, the detective leading the inquiry said he believed a 30-mile stretch of the A714 between Girvan and Newton Stewart would lead them to Emma’s body.

Detective Chief Inspector Martin Fergus appealed for information on a black Mercedes seen on the road on Monday, April 29 – the day after Emma was last seen – and a black Jaguar on April 30.

The aircraft flew over Loch Mayberry in the Galloway forrest near Barrhill

Willox is alleged to have murdered Emma and attempted to defeat the ends of justice.

He made no plea or declaration when he appeared in court and was remanded in custody.

The plane’s mission took on an air of mystery yesterday when police denied they had used it in the search for Emma.

A Police Scotland spokeswoman said: “We are not ruling out any areas and the searches are continuing.”