The incident occured on the same day that a United Kingdom judge upheld an arrest warrant against Assange, who is wanted by London police for breaching his bail conditions after surrendering to authorities, and then absconding, in 2012.
A warrant was subsequently issued by Westminster Magistrates' Court.
Assange has refused to leave the embassy, claiming he fears being extradited to the United States over WikiLeaks' publication of secret USA military documents and diplomatic cables in 2010.
Arguments were made by Assange's legal representatives that the warrant should be dismissed as it had "lost its goal and function" following an investigation into a sex-related allegation being dropped.
But Arbuthnot said such issues could be considered only if Assange were to be brought to court to explain his failure to surrender to bail.
The offence carries a maximum penalty of one year in prison, and Assange remains in the Ecuadorean Embassy.
But Aaron Watkins, for the Crown Prosecution Service, told the court Mr Assange's application was "absurd".More news: England rack up seven tries in emphatic win over Italy
British prosecutors had opposed the removal of the warrant, saying Assange shouldn't be immune from the law simply because he has managed to evade justice for a long time.
The judge is now considering written submissions from Assange's lawyers on other grounds.
The WikiLeaks founder claimed political asylum in July 2012 after facing rape allegations.
Assange sought asylum in the embassy because he feared Swedish police would eventually extradite him to the United States, where he could face decades in jail over WikiLeaks' publication of thousands of secret military documents in 2010.
The court heard that the 46-year-old was suffering from a bad tooth, a frozen shoulder and depression because of his long stay in the embassy.
They said Assange's medical problems included "a awful bad tooth, frozen shoulder and depression".
The Australian was being investigated for rape in Sweden, which he has denied. Mr Assange has been released on bail, 2.
"The Metropolitan police will continue to be obliged to arrest Assange should he set foot outside the Embassy".