A teenager's house party ended with attacks on police, 19 arrests and allegations of animal abuse after news of the event was promoted on Facebook.
Richard Collis, a pastor's son, charged schoolmates $10 to attend his birthday barbecue at his Levin home last Friday while his mum and dad were out of town for the weekend.
He has since issued a public apology after an estimated 300 revellers turned up to the tidy home on a lifestyle block outside town.
Senior Sergeant William Roy of Levin police said those arrested face charges including assault, disorderly behaviour, fighting in a public place and possession of cannabis.
Mr Roy said police heard about the party in the afternoon. They contacted Collis and then his parents, who rang back to say they had checked with their son and everything was all right.