Squatters have taken over a house thought to belong to Saif al-Islam Gaddafi, the second son of the Libyan dictator.
A group calling themselves "Topple the Tyrants" occupied the £10 million house in Hampstead Garden Suburb in north London today.
The group have vowed to remain in place until the property's assets are returned to the Libyan people, according to the BBC.
Spokesman Montgomery Jones told the BBC: "We will stay here until we can be sure the property will be returned to its rightful owners.
"The police came to look around, then went away. The house isn't occupied at the moment but there are things to sit on."
The group said the property was managed by the Gaddafi family through a holding company registered in the British Virgin Islands.
In a statement, it said: "We didn't trust the British government to properly seize the Gaddafi regime's corrupt assets, so we took matters into our own hands.
"In the meantime, we want to welcome refugees from the conflict in Libya and those fleeing tyranny and oppression across the world.
"We stand in solidarity with the Libyan people."
A Scotland Yard spokesman said: "Police were called to an address in Hampstead Garden Suburb at approximately 12.50 today to reports of unknown people entering the premises. At this time it is being treated as a civil matter.
"There have been no arrests."
Colonel Muammar Gaddafi and his family have been stripped of diplomatic immunity - preventing them from entering the UK - and banks and other bodies have been told by the Treasury to prevent them using UK-held funds and assets.
No immediate figure was put on the total value of the assets, including cash, shares, bonds and property, but some reports put it as high as £20 billion.
An export ban has also been placed on a "significant" consignment of Libyan banknotes - with a face value of around £900 million - amid fears it would be used to fund violence against protesters.
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