Ann Clwyd has called for a fresh review into Welsh hospitals, saying death rates in "one or two hospitals in Wales are higher than at the Mid Staffordshire hospital."
"That should be a very clear signal that something is wrong. Somebody ought to be analysing it," she said.
Fresh claims of serious neglect have been uncovered by a special ITV News investigation at a hospital already at the centre of a major police investigation and an independent review ordered by the Welsh Government.
The Cynon Valley MP published a report into the way complaints int the NHS in England in October and has called for an inquiry into Welsh hospitals with higher-than-average mortality rates.
She has been demanding better treatment of hospital patients since she complained that her own husband was neglected before his death at the Heath Hospital in Cardiff last year.
Abertawe Bro Morgannwg University Health Board has issued a statement relating to patient care at the Princess of Wales Hospital.
There are fresh claims of serious neglect at a hospital at the centre of a major police investigation and an independent review in Wales.