Ireland's heath service is appointing an external investigator to head the inquiry into how an Indian woman died of blood poisoning after she was repeatedly refused an abortion in an Irish hospital.

Savita Halappanavar's husband, Praveen, said his wife asked for a termination in University Hospital Galway after being told her baby would not survive. He claimed she was refused a termination because medical staff at UHG believed there was still a foetal heartbeat even though his wife died in agony afterwards.

The Health Service Executive's national incident management team has confirmed it is investigating the 31-year-old dentist's death last month.

In a statement, the HSE said it was in the process of appointing an independent, external report in obstetrics and gynaecology to join its inquiry team.

On Thursday night candlelit vigils were held in memory of Halappanavar in Dublin, Galway, Cork and Limerick, and the Irish embassy in London was picketed. In the largest of the demonstrations, 2,000 people protested outside the Irish parliament over what they called the "political cowardice" of the country's leadership on the abortion issue.

A mass protest against Ireland's abortion ban is to be staged in Dublin on Saturday and there are calls for other Irish embassies across the EU to be picketed at the weekend.

Halappanavar's death has prompted calls for the current Fine Gael-Labour coalition to legislate on abortion based on a 1992 ruling that terminations could be permitted in Irish hospitals if there was a "real and substantive" risk to the life of the mother. Irish governments over the last 20 years have ignored demands that they lay down specific guidelines on abortion for doctors and medical teams.

The Irish cabinet is due to discuss an expert report on abortion which centres on a European court of human rights ruling last year that found in favour of three women who claimed the abortion ban was a breach of their human rights.