Graham Smith from the Republic campaign group was arrested on Coronation day
Anti-monarchy protesters arrested during the Coronation say they are considering legal action against the Met Police.
Graham Smith, chief executive of Republic, was among those held and said police had now told him there would be no further police action taken.
But he said he wanted a “full inquiry” into the “disgraceful episode”.
The Met said it had “a duty to intervene when protest becomes criminal and may cause serious disruption”.
Mr Smith said he had spent months consulting with officers about his group’s protest plans, and said in a statement on Twitter that his group would be “speaking to lawyers about taking legal action”.
The police force said it made 64 arrests on the day of the Coronation, with four people charged so far.
Prime Minister Rishi Sunak gave his backing to the police, saying they act independently of the government and did what they thought was best.
Mr Smith said he had been held for 16 hours on the morning of the Coronation after being stopped by officers who suspected him and group members of carrying “lock on” devices to tie themselves to inanimate objects.
“They also said they had intelligence, which is untrue,” he told BBC Radio 4’s Today programme.
“If they did have intelligence their intelligence officers are either lying or incompetent because there was never any discussion, thought, email, message, anything that suggested any intent to do anything disruptive.”
Mr Smith added that, after months of discussions with the Met, the force had “repeatedly said, right up until Friday, that they had no concerns about our protest plans, that they were well aware of what we were going to do and they would engage with us and not disrupt us”.
He continued: “So they’ve repeatedly lied about their intentions, and I believe they had every intention of arresting us prior to doing so.”
Mr Smith also rejected suggestions his arrest, along with other protesters, was necessary to limit disruption to the Coronation.
The Met Police said the Republic members were arrested on suspicion of conspiracy to cause a public nuisance.
Four people arrested on the day of the Coronation have been charged so far, including one under the Public Order Act; one with suspicion of causing a religiously aggravated offence; and two for the possession of Class A drugs.
All four will appear in Westminster Magistrates’ Court later this month.
Forty-six people have been granted bail, under charges including conspiracy to cause a public nuisance and a breach of the peace.
Met Police Federation chairman Ken Marsh said officers “police without fear or favour,” insisting the force had done “an incredible job” policing the Coronation.
He told the Today programme: “We have to take into consideration everything that at that moment is put in front of us. If individuals intend to cause an incident which will affect others near them or around them… then we take action to deal with it.
“Protesting can take place in this country, but it’s to the level of which you perform that protesting that we have to balance and deal with.”
