A hot tub party host who claimed he "didn't believe" in lockdown rules has been reported for a court summons.
Nottinghamshire Police arrived at an address in Mansfield to find people from five different households mixing.
Such mixing is banned under restrictions introduced to tackle the second wave of COVID-19.
In September, after the rule of six was introduced, Boris Johnson said members of the public should not report neighbours who breach it unless they are having "Animal House" parties with "hot tubs and so forth".
In a statement, the force said when the homeowner was asked to give his details, he refused.
When officers tried to explain the law, he allegedly replied "he didn't believe in the COVID-19 legislation" and "continued to be obstructive".
The 32-year-old was reported for a summons to a magistrates' court, while six people at the party were dispersed.
Assistant Chief Constable Steve Cooper said: "I find it pretty astonishing that anyone would think it is OK to behave in this sort of way when there has been clear guidance given around not mixing households.
"We are still very much in a lockdown as a nation and we need to keep abiding by these laws.
"COVID is real and has the potential to kill people and we cannot forget this. Everyone has to do their bit to limit the spread of the virus and keep people safe.
"Our approach has always been to engage, explain and encourage people to act responsibly, but we won't hesitate to use enforcement action where necessary as we continue to do all we can to protect our communities."
In a separate incident, a homeowner was issued a fixed penalty notice after police came across a party attended by 17 people from different households in Mansfield in the early hours of Tuesday.
Latest NHS data showed Sherwood Forest Hospitals NHS Trust, which runs Mansfield's King's Mill hospital, had 92 COVID-positive patients in its beds last week, of whom 12 were on ventilators.