Julian Assange's son, Daniel, says he does not live at a house in the Melbourne suburb of Carlton where a crowd gathered earlier today.

A number of police were sent to the address to move the crowd on, but Daniel Assange said via his Twitter account that he had moved out years ago.

His father has been denied bail by a British court and is facing extradition to Sweden where two women claim he coerced them into unprotected sex.

Appearing in the Westminster magistrates court overnight, just hours after handing himself in to British police, Mr Assange spoke only to confirm his name and Victorian address and to say he did not consent to being returned to Sweden.

The address in Carlton where the crowd gathered was not the one given by Julian Assange when he appeared in the London court.

As he faces what could be a lengthy extradition hearing, Mr Assange defended his website's release of secret cables and hit out at the Australian Government for failing to protect one of its citizens.

In court to support him were filmmaker and journalist John Pilger, socialite Jemima Khan and film director Ken Loach. Each offered $32,000 as surety.

His supporters say he is being targeted because foreign leaders are embarrassed by the leaks.

"This whole case in Sweden is a political stunt," Pilger said.

"When the chief prosecutor abandoned this case - saw no worth in it - then it was only reactivated with the intervention of a right-wing politician in Sweden. It stinks."

Mr Assange's extradition hearing is due to begin next Tuesday.

Meanwhile, the embattled WikiLeaks website is continuing to release secret US diplomatic cables despite Mr Assange's arrest.

Newly released cables reveal that two years ago Saudi Arabia wanted a military intervention in Lebanon to destroy the Hezbollah group.