Cops busted a massive party with as many as 400 people who were stuffed in a Long Island mansion early Monday morning.

Officers responded to the 10-acre mansion in Brookhaven around 12:30 a.m. and began shutting down the party, which violated the state’s mandate of keeping small gatherings to 10 people, according to Suffolk County police.

Police say the owner rented the mansion to the host on Airbnb.

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“He made it very clear to the person that was renting the house, who we believe was from New Jersey, what the rules were in New York, that they could not have a gathering of more than 10 people and he did supply documentation that that message was communicated,” Suffolk Police Chief Stuart Cameron told News 12 Long Island.

Cops have not identified the host, who faces a nuisance charge for violating public health law and a fine of up to $15,000, according to Newsday.

This article first appeared in the New York Post.