A health watchdog is to investigate the care of people with learning disabilities across England, after allegations of abuse at one NHS trust.
Budock Hospital, the centre of the commission's investigation
The Healthcare Commission said early stages of an investigation at Cornwall Partnership NHS Trust found "significant failings".
Regional health chiefs have sent in an external team to improve services.
The Healthcare Commission said it wants to ensure the problems seen in Cornwall are not occurring elsewhere.
It has written to Health Secretary Patricia Hewitt to outline the initial findings of their Cornwall investigation, which began in June.
The concerns relate to Budock Hospital, near Falmouth - a treatment centre for 14 in-patients - and some of the 45 houses occupied by groups of three or four people with learning disabilities.
These homes look after around 170 residents who get support with daily living and access to healthcare.
The Commission for Social Care Inspection (CSCI) is also taking part in the Healthcare Commission investigation.
Quality services 'a priority'
The commission stressed its concerns do not relate to all houses and treatment centres run by the trust and it had seen good practice during its inquiry.
But it said it had acted before completing its investigation to safeguard people with learning disabilities and "establish an appropriate model of care".
Six cases relating to alleged abuse have been referred to the Cornwall Adult Protection Committee.
The Cornwall Partnership NHS Trust said seven members of staff had been suspended before the commission's investigation began.
Chief executive Tony Gardner welcomed the appointment of the external team.
He added: "While we accept the concerns in some areas of our work, we are pleased that the Healthcare Commission have recognised examples of good practice in our service and that they have emphasised that these concerns do not relate to all areas of our learning disability service.
Jayne Carroll, director of service strategy at the South West Peninsula SHA, which called in the external team, said: "Our priority is to ensure that high quality services are consistently provided to people with learning disabilities."
The Healthcare Commission now plans to step up its audit and inspection of services across England for people with learning disabilities.
It will then develop an audit of NHS inpatient services which is likely to lead to a series of spot checks where there is evidence of concern.
Anna Walker, Healthcare Commission chief executive, said: "It is absolutely vital that serious allegations are thoroughly investigated.
"We must do everything possible to protect this group of people from abuse and reassure those who have put their trust in this service."
She added: "I sincerely hope that this is an isolated problem, but we need to make absolutely sure."
David Congdon, head of campaigns and policy at Mencap, welcomed the investigations.
"People with a learning disability are amongst the most vulnerable in society. Any neglect or abuse is intolerable.
"People with a learning disability should have the same choices and opportunities that most people take for granted to choose how, where and who they live with.
"The model that generally provides this, for the majority of people with a learning disability, is supported living but it is crucial that people are provided with an appropriate level of support to lead fulfilling lives."