anti social neighbours in flats

General Discussion

I would value advice on dealing with a flat owner who has sublet his flat to an addiction charity. It is used as a hostel for people with substance abuse and their behaviour is causing a nuisance to the families in the other flats.
The lease forbids subletting other than to families and also forbids nuisance to other residents.I can act as freeholder or via managing agent or as an owner of flats in the block.
Has anyone taken legal action under this kind of lease before? Did it work?