An investigation has been launched after a woman died in an ambulance queuing outside a Welsh hospital.

It has been reported the woman may have been waiting in the vehicle outside Morriston Hospital in Swansea, south Wales, for up to 40 minutes.

Her death came as the British Medical Association (BMA) said the NHS in Wales was facing "imminent meltdown".

The Welsh Ambulance Service and Abertawe Bro Morgannwg Health Board confirmed they had launched a review into the death.

In a joint statement they said: "The emergency department at Morriston Hospital has been very busy with a high number of ambulances arriving in a short space of time.

"Escalation plans have been activated and staff across the hospital are working closely with colleagues from WAST (Welsh Ambulance Service Trust) to keep delays to a minimum."

Health officials confirmed the patient arrived at Morriston from another hospital at about 3:05pm yesterday.

A statement read: "The patient was assessed immediately upon arrival and remained in the care of a doctor and the ambulance crew whilst waiting to be admitted into hospital. Sadly, at approximately 3:40pm the patient passed away. We wish to express our sincere condolences to the patient's family."

In recent months there has been growing concern about Wales's NHS as well as ambulance service performance. Yesterday, the British Medical Association called for an independent inquiry into the health service.

The organisation, which represents around 7,000 doctors in Wales, published a report listing numerous problems it believes the Welsh Government must address.

BMA Welsh Council chairman Dr Phil Banfield said members' feedback indicated the service was struggling to cope.

He said: "The sooner this (inquiry) takes place, the better. There's a lot of sticking heads in the sand still going on. Our greatest fear is it will become impossible to have an NHS in Wales."