Oxford's Slade House under investigation
A health regulator is investigating whether an NHS assessment and treatment unit in Oxford breached its licence.
Unannounced visits by the Care Quality Commission (CQC) at Slade House in Headington found dirty toilets, outdated equipment, and broken fittings.
Paul Streat, regional director of Monitor, said the regulator was acting in the interests of local patients.
Southern Health NHS Foundation Trust has closed the site to new admissions.
Slade House provides health care across two sites for people with mental health needs, learning disabilities, and problems with substance misuse.
The CQC inspected the facilities on 16, 17, and 23 September.
Monitor said it wanted to know if the problems uncovered meant improvements were needed in how the trust was run and if it had "breached its licence to provide healthcare services".
Paul Streat added: "We are acting in the interests of local patients to find out what went wrong and to help prevent it from happening again."
Katrina Percy, chief executive of the trust, said she was "concerned" about the report and an internal investigation had been launched.
Southern Health NHS Foundation Trust provides care services at 200 sites across the south of England.