Ten members of staff have been suspended after the death of an elderly woman.
The 88-year-old woman died at Prince Charles Hospital in Merthyr Tydfil today after suffering an "unexplained and serious injury" at Ysbyty Cwm Cynon in Mountain Ash last Thursday.
Cwm Taf University Health Board say the staff were on duty the night before and the morning after the injuries were sustained. It added the suspensions are a "precautionary measure".
South Wales Police say they are investigating and four people are assisting officers with their enquiries.
A spokesperson for Cwm Taf University Health Board said:
'On Thursday morning, as part of routine patient care, a patient at Ysbyty Cwm Cynon was identified as having an unexplained injury.
'Appropriate arrangements were made for transfer to Prince Charles Hospital in Merthyr Tydfil. As is always the case in such a situation, the Health Board initiated a multi-agency strategy meeting to be held to consider the circumstances. This took place the following day.
'Staff on duty at the time are in the process of being interviewed to assist the investigation and the family have been kept fully informed of the situation.'
The health board added it has not made any link between the patient's injuries and her death.
A post-mortem is due to take place tomorrow.