Seven protesters have been arrested after clashing with police and fans of controversial British commentator Milo Yiannopoulos at his secret Sydney event.

The protesters were later charged with offences including breach of the peace, assault police, hinder police, affray and failing to comply, a police spokeswoman said.

The function venue Le Montage in Lilyfield was heavily guarded with mounted police, officers on bicycles, riot squad, marine police and police vans barricading the event after several arrests were made at his Victorian event on Monday night.

The venue wasn't revealed until an hour before the event was scheduled to start and the surrounding streets were all closed off in the hours leading up to his scheduled speech.