Police said they halted a church service in London on Good Friday because worshippers "were clearly not socially distanced".
Officers attended Christ the King Polish Church in Balham at around 6pm on Friday after receiving reports of "crowds of people queuing outside", Sky News reports.
The church was not allowed to finish the service and parishioners were told to go home or else risk being fined £200 or even arrested if they failed to provide their details.
An officer was filmed telling parishioners that the gathering was "unfortunately unlawful under the coronavirus regulations" and that worshippers were "not allowed to meet inside with this many people under law."
He added, "It's Good Friday and I appreciate you would like to worship, but it is unlawful."
The Metropolitan Police said that no fines were issued at the service.
"Officers attended and found a large number of people inside the church. Some people were not wearing masks and those present were clearly not socially distanced," it said in a statement.
It added that officers were concerned about the risk of transmission.
"As such, officers made the decision that it was not safe for that particular service to continue," the statement said.
The church said its congregation obeyed the order to leave "without objection" but it has denied any wrongdoing and said that "the police brutally exceeded their powers by issuing their warrant for no good reason, as all government requirements were met".
"We believe municipal police officials have been misinformed about the current place of worship guidelines, saying the reason for their intervention is the continuing ban on public celebration in places of worship in London due to the lockdown on January 4, 2021," it said in a statement.
"We regret that the rights of the faithful have been wronged on such an important day for every believer, and that our worship has been profaned.
"We informed the superiors of the Polish Catholic Mission in England and Wales about this incident. We asked the police authorities to explain the incident and we are waiting for their response."
The church, which plans to hold remaining Easter services as scheduled, has also suggested that members of the congregation complain to the Met Police over the incident.
"The latest government guidelines of March 26, 2021 and the Episcopal Conference of England and Wales on the experience of Holy Week, clearly allow - with all sanitary rules - to be celebrated in places of worship with the participation of the faithful," the statement added.
"We ask everyone to observe the current sanitary requirements in the Church and the space of social life, and to pray that such situations will not be repeated."
Under current guidelines, face coverings must be worn in church but there are "valid exemptions for some individuals and groups to not wear a face covering in these settings", including those leading the services and those who assist them.
Social distancing rules require that visitors to a place worship "be 2 metres apart or more than 1 metre apart as well as taking extra steps to stay safe (such as wearing face coverings) to reduce the risk of transmission". Worshippers are also not allowed to mingle with anyone outside their household or support bubble while inside a place of worship.