An Australian human rights lawyer and WikiLeaks supporter has reportedly been placed on a watch list and requires permission from the Department of Foreign Affairs to fly home.
Jennifer Robinson claims she was stopped at Heathrow airport this morning, only days after meeting WikiLeaks founder Julian Assange.
Ms Robinson said she was told she was on an inhibited travel list and unable to enter Australia without permission from the Department of Foreign Affairs.
"Just delayed from checking in at LHR because I'm apparently 'inhibited' - requiring approval from Australia House @dfat to travel," she tweeted.
An airport security guard told the London-based human rights lawyer she "must have done something controversial" and said he would have to phone the embassy, she said.
She then tweeted, "@dfat Please explain: What is the 'inhibited' travel list? And why am I now apparently on it?"
The Department of Foreign Affairs said it was not aware of any Australian government restrictions on Ms Robinson's travel.
"As an Australian with a valid passport, she would be free to return to Australia at any stage," a spokesman said.
"The UK border authorities or airline of travel may be able to provide further insight on claims that she was impeded from boarding her flight."
WikiLeaks expressed concern about the incident, which comes only a day after Mr Assange's talk show The World Tomorrow premiered on TV network Russia Today with an interview with Hassan Nasrallah, the leader of the militant group Hezbollah.
"Jennifer Robinson (@suigenerisjen) met with Assange on Monday. Assange show broadcast Tuesday. Australian watchlist incident Wednesday," WikiLeaks tweeted.
Robinson's twitter name @suigenerisjen began trending in Melbourne and Sydney shortly after the incident. It is believed she was eventually able to board the plane, which is flying to Sydney via Hong Kong.
Greens Senator Scott Ludlam fired off an angry tweet to the Department of Foreign Affairs, requesting information about why the human rights lawyer was allegedly placed on a watch list.
"@DFAT care to explain why @suigenerisjen is on your watch list? what kind of threat do human rights lawyers pose exactly? #auspol," he tweeted.
Ms Robinson is the director of legal advocacy at the Bertha Foundation in London.
She advises WikiLeaks and Mr Assange and acted for Mr Assange in extradition proceedings in Britain.
She recently recently appeared on behalf of WikiLeaks at the Bradley Manning court proceedings in the United States.
The Rhodes scholar is due to speak at a Queensland Public Interest Law Clearing House event in early May and was travelling to Australia to speak on a panel titled Lawyers on the Frontline at tomorrow's Commonwealth Lawyer's Association's Regional Law Conference.
Attorney-General Nicola Roxon will speak about terrorism and human rights at the same event.
The UK Border Agency has been contacted by The Age but is currently closed.