Anti-terrorist cameras have been installed at Edinburgh Airport as police start to tighten security in the run up to the G8 summit.
Automatic Number Plate Recognition (ANPR) cameras have been placed above the A8 near the Hilton Edinburgh Airport hotel.
Three cameras have been linked to the police database to help them immediately identify cars going in and out of the airport.
In the last couple of years they have been introduced by forces across the country - including those who guard Heathrow - to watch out for potential terrorists, recover stolen goods, combat drugs trafficking, and catch criminals.
In London's financial district they have been used to protect the City from a terrorist attack.
Lothian and Borders Police are staying tight-lipped about why they have been installed near the airport. A spokesman would only say: "They are part of airport security measures."
However, an industry expert said the technology could be used to prevent an attack on the airport.
In November, airport bosses paid Appian Technology GBP 70,000 to install a parking guidance information system to monitor the numbers of vehicles using the car park and improve customer service. The company which installed it also provides ANPR cameras, although it is not behind the ones placed on the A8.
However, it was responsible for installing cameras in London.
Appian Technology's Nigel Lidster, regional sales manager for the UK and Ireland, said: "We've not installed ANPR cameras around Edinburgh Airport - but that is not to say someone else hasn't.
"From a security perspective it is like installing a ring of steel.
"When we provided ANPR for the City of London it was as a result of IRA activity.
"It captures number plate information which is then verified against databases.
"It means police can keep a track of cars going in and out of the City of London, and recognise ones which have been stolen."
A spokeswoman for the airport said she was aware the cameras had been installed, but it said it is nothing to do with the owner BAA.
She said: "They are Lothian and Borders Police cameras. They have been installed for their own benefits and for their own reasons."
Scots terrorism expert David Capitanchik of Robert Gordon University in Aberdeen said police and security forces will be on high alert over the next few weeks.
He said: "They will want to see what sort of people are coming into the country and who is picking them up at the airport.
"Security at entry points will be a very high priority. People will be thoroughly searched."
Mr Capitanchik added: "My understanding of these cameras is that if they are installed around the airport they will provide a means for someone in police headquarters to see what is going on around the perimeter.
"They would probably have been installed anyway. But the police would have wanted to get them in place before G8.
"There's great concern about being able to see who is coming into the country.
"There will be people coming in to demonstrate and that may be one of the reasons these cameras have been installed."
The installation of the ANPR cameras in Edinburgh follows a security scare at Prestwick Airport, in Ayrshire, where world leaders will fly next month before the G8 summit in Gleneagles. Three men stole computer equipment worth an estimated six-figure sum from the cargo unit after threatening a staff member with a knife on Sunday. Since then, security chiefs at Prestwick have promised to step up security.
Although world leaders will be landing at Prestwick, many senior delegates who will be involved in the summit will still be flying to the Capital.
Edinburgh Airport was put on standby last October when it was thought the US Presidential jet Air Force One could arrive there.
Talks took place between airport chiefs, the Foreign and Commonwealth Office and the Scottish Executive over procedures that needed to be carried out to welcome the delegates.
But it is believed Air Force One will now land at Prestwick Airport, although entourages of G8 countries will still use parts of the Edinburgh Airport which will be sealed off to other domestic passengers.
