Insurers of the valuable Leonardo da Vinci painting which was stolen from a Scottish castle have offered a reward for information leading to its return.
"A work of peace and beauty"
The exact amount set aside is said to be dependent on the quality of information received.
A fine arts loss adjuster said the painting was one of the most important stolen in the UK in the last 70 years.
Four men raided Drumlanrig Castle on Wednesday and fled with the Madonna with the Yarnwinder, which is thought to be worth about £30m.
Two men posing as visitors overpowered a female member of staff and escaped with the painting.
A white Volkswagen Golf GTI - which was used by the four men in their escape - was found abandoned in woods near the castle.
Police are carrying out forensic tests on the car and are believed to be searching for a second vehicle.
Fine arts loss adjuster Mark Dalrymple said the painting's value should not be underestimated.
He said: "Some have likened it to the theft of the Mona Lisa - which fortunately did come back."
Dumfries and Galloway Inspector Phil Stewart said he believed the robbers had been to the castle before.
The da Vinci work, which experts say was painted between 1500 and 1510, depicts the Madonna with the infant Jesus holding a cross-shaped yarnwinder.
It is said to symbolise the crucifixion of Jesus.
The police hunt for the gang has been stepped up
Insp Stewart said: "Two men posing as bona fide visitors entered the castle, entered the room where the painting was on display and overpowered a female member of staff.
"They took the painting and then made good their escape out of the castle."
Insp Stewart added that descriptions of the robbers and the getaway car had
been passed to Interpol.
Interpol, the international police organisation, has thousands of major art works on its database that are missing around the world.
Drumlanrig Castle is home to the Duke of Buccleuch, who is one of Scotland's richest men.
Richard Dalkeith, the earl of Dalkeith and the son of the Duke of Buccleuch, said his family was "shocked and dismayed".
He said: "This is a treasure that has been in my
family for more than 250 years.
"It's the most beautiful work of art by one of the greatest painters in the world.
"It is a work of such peace and beauty and the thought of it being sort of torn away from us like this is very sad indeed.
"Thousands of people have come over the years to see it. It's not been shut away and just enjoyed by us."