Q105: I think my friend/partner has been arrested and is in the cells, how can I find out?

The police are not allowed to inform anyone of the fact that a person has been detained without their express permission (unless the person in custody is a juvenile).

It is very unlikely that the custody staff will give you information about any person detained in the cells. The detained person does have the right to a phone call and the right to have someone told of his or her detention (except in specific circumstances).