Vivienne Westwood, dressed in yellow, was locked into a giant bird cage outside London's Old Bailey court on Tuesday in a stunt to show her support for the WikiLeaks founder Julian Assange, who is fighting extradition from Britain to the United States.
"I am Julian Assange," fashion designer Westwood said. "I am the canary in the cage. If I die down the coal mine from poisonous gas, that's the signal."
"Free Assange," she said.
Assange is wanted by the authorities in the US to stand trial for 18 offences, including conspiring to hack government computers and espionage.
Last year, the US began extradition proceedings after Assange was dragged from the Ecuadorean embassy in London, his refuge for almost seven years.
Assange made international headlines in early 2010, when WikiLeaks published a classified US military video showing a 2007 attack by Apache helicopters in Baghdad that killed a dozen people, including two Reuters news staff.
To some, Assange is a hero for exposing what supporters cast as abuse of power by modern states and for championing free speech. But to others he is a dangerous rebel who has undermined US security.