LONDON — A British judge on Monday ordered supporters of Julian Assange to pay thousands of pounds they promised for his bail because the WikiLeaks founder violated the conditions for his release.

The 41-year-old Assange violated a condition to report to a police station daily when he sought refuge at the Ecuadoran Embassy in London, where he has been holed up since June 19 to avoid extradition to Sweden to face questioning over allegations of sex crimes.

The WikiLeaks founder and his supporters claim that the Swedish sex case is part of a Washington-orchestrated plot to make him stand trial in the United States over his work with WikiLeaks, which has published thousands of secret US diplomatic cables and other documents. Both Sweden and the United States reject that assertion.

Vaughan Smith, a former BBC journalist who hosted Assange at his country house for more than a year as the WikiLeaks founder fought extradition, was among the nine supporters who had argued that they should not be punished for trying to ‘‘serve the public interest’’ in the case.

But Chief Magistrate Howard Riddle on Monday ordered them to pay $150,000 by Nov. 6, saying that although he accepted that the supporters had acted in good faith, they had failed in their ‘‘basic duty’’ to ensure Assange surrendered.

‘‘They must have understood the risk and the concerns of the courts,’’ he said in his ruling, ordering each of the nine to pay part of $224,300 originally pledged.

Still, the judge said he respected the supporters for acting against their own self-interest in refraining from urging Assange to surrender.

British officials say Assange will be arrested if he steps outside the embassy.