Emergency workers were attacked as they tried to break up a student party just outside of Wigan that attracted people from across the North West.
Officers were called to the West Lancashire property overnight and discovered a brazen breach of Covid-19 restrictions with the premises being used to host a house party with up to 20 people inside.
The scenes also saw officers and an emergency worker attacked and one man arrested.
Stashes of cannabis and boxes of nitrous oxide were seized and the student who organised the party now faces a £10,000 fine, LancsLive reports.
The party comes after new laws came into effect on Friday night to tackle illegal gatherings during the pandemic, with fines of £800 for anyone attending a house party with over 15 people.
Sergeant Scott, of Ormskirk and Rural West Lancashire Police, said the force was 'appalled' by the incident and said the party-goers behaviour was 'unacceptable'.
He said: "I am disappointed to report that overnight we had to attend a gathering of upwards of 20 individuals that felt it necessary to travel from various places in the North West for a house party.
"Their behaviour is unacceptable. Not only did they contravene various restrictions, some assaulted officers at the scene.
"Fixed penalty notices were issued to those attending, quantities of cannabis were seized along with boxes of nitrous oxide.
"A male from the Manchester area was arrested for assaulting an emergency worker and contravening the regulations.
"The student who organised and held this event has been issued with a fixed penalty notice and now faces the prospect of a £10,000 fine.
"I am appalled by this behaviour and hope this stands as a deterrent to those who wish to organise future events like this during this pandemic."
The exact location of the illegal house party has not been disclosed by police.
The country remains in national lockdown meaning people must stay at home unless necessary.
Under the current rules, people may only leave their homes to shop for basic necessities, to go to work if they cannot reasonably do so from home, to exercise once a day with your household, support bubble or one other person, to meet your support bubble where necessary or to seek medical assistance.
