Three men have been arrested today following an investigation into drugging and sexual assaults relating to a Christchurch inner city bar and restaurant.

Police executed a number of search warrants in the city today and three men, aged 33, 34 and 36, were arrested.

The trio are facing charges of supplying a class B controlled drug, stupefying, rape, and unlawful sexual connection.

They will appear in Christchurch District Court this afternoon.

Detective Senior Sergeant Scott Anderson of the Canterbury Adult Sexual Assault team said the case highlighted the importance of taking care of each other when on a night out.

"It's crucial that when you are out socialising, you keep an eye on your drink and stay on guard for this type of criminal activity," he said,

"But it's also really important to look after your mates – if anyone feels drowsy or suddenly 'out of it', take them to a safe place, and don't leave them alone."

As the matter is now before the courts, police are unable to comment further.