More than 40 people face being slapped with a £800 fine after being caught at an illegal rave in the vault of a disused bank.
Dramatic bodycam footage collected by the Metropolitan Police shows the moment officers broke up the illegal party in west London.
Officers patrolling the area had heard loud music coming from a property on Hortus Road in Southall, when they discovered the party in the derelict building just before 9am last Sunday.
Those in attendance had made their way into the premises through a gap in a fence, police said, with DJ equipment and speakers having been set up inside.
The officers entered the venue and reported all 44 people inside for consideration of a fixed penalty notice of £800 before removing them from the premises.
The Met's Detective Chief Inspector Thomas Bowen branded the revellers' behaviour "selfish" as the gathering could turn out to be a "breeding ground" for Covid-19.
The footage shows techno music pumping at full blast when an officer storms in and tells the revellers: "How many people... Right everyone's detained alright, you can't leave."
Mr Bowen, from the Met's West Area Command Unit, which covers the area, condemned the the party-goers saying such behaviour could result in lockdown lasting longer than expected.
"It is disappointing some selfish people still insist on breaking Covid regulations," he said.
"We are all excited about the prospect of returning to normal in June - and some changes to restrictions are imminent - but behaviour like this risks undermining the road map out of lockdown and could potentially cause further delays by creating a breeding ground for the virus.
"We will continue to do our part in shutting illegal events like this down and taking action where necessary."
