An Essex hospital could be responsible for more than 500 preventable deaths in the past two years.
An NHS investigation -following the Stafford Hospital scandal- found Basildon Hospital registering higher than expected death rates. Mortality ratios were "persistently high" between July 2010and June 2012, according to the Health and Social Care InformationCentre.
Upto 2,500 avoidable deaths could have taken place at Basildon over thelast decade.
Last November the Care Quality Commission (CQC) performed an unannounced inspection at Basildon and Thurrock University Hospitals NHS Foundation Trust following the death of a girl and a medication overdose of a baby.
Itis understood that the girl was treated at the trust before she wastransferred to St Mary's Hospital in west London where she laterdied.
The CQC found that "rapid and sustainable improvement" was needed at the trust and ordered an independent investigation into the paediatric services.
A spokesman for NHS England said today: "We are currently in stage one of the review: gathering and collating information and dataalready available about, among other things, clinical quality and outcomes, as well as the views and feedback of patients and staff. We are assessing and analysing this evidence to develop key lines of enquiry.
"There is a huge amount of information available in the NHS. It is vital that we fully identify, collate and analyse all this data so that we can completely understand each hospital's unique circumstances and case mixes and plan review visits accordingly.
"Regional review teams will carry out stage two: rapid response reviews at the 14 identified hospital trusts. These review visits will happen throughout May and June."