In June, marchers at the annual Al-Quds Day protest in London exploited a legal loophole to wave Hezbollah flags.
While the military wing of the Shi’a Islamist group is banned, its political wing is not, allowing marchers to claim they were supporting the unproscribed section.
Following the Al Quds day protest, police confirmed to the JC they had launched a probe on whether the display of the flags contravened UK terror laws.
Labour MP Louise Ellman and Mayor of London Sadiq Khan had been among those to write to the Home Secretary calling for action.
Police estimated that around ,3000 people turned up for Saturday’s anti-Balfour march and there appeared to be no instances of the flags being raised.
The JC has contacted the Metropolitan Police for official comment.