An Iranian asylum seeker who suffered a miscarriage in a Christmas Island detention centre was refused ultrasound by medical staff, it has been claimed.

The woman, known only as Elham, was 13 weeks pregnant when she complained of feeling unwell. Nurses and doctors at the refugee camp told her there was nothing wrong with her, she alleged.

"I was going unconscious sometime and I got bleeding – and even with this situation they didn't pay attention to me and told me it's normal, no need to go to hospital," Elham said.

As her condition deteriorated, a member of staff drove her to hospital where an ultrasound revealed that she had miscarried. Doctors told her husband that the baby might have been saved if she had been brought in earlier.

Weeks after the miscarriage, Elham contacted the hospital to ask for another ultrasound to find out what had gone wrong but hospital staff refused, she said.

"Every time I am asking them, they keep telling me that you are in detention centre and should not expect a lot."

Doctors working for the International Health and Medical Services (IHMS) used Elham's story as an example of what they say are low medical standards in the detention centre.

They wrote a "letter of concern" in which they revealed "unsafe practices and gross departures from generally accepted medical standards" experienced by asylum seekers.

Ultrasonographers visit the island only every few months and, according to the doctors, "catered primarily for local residents".

After identifying Dr John-Paul Sanggaran as the principal author of the letter, IHMS said that he had been employed on Christmas Island during "a period of high intensity, with an unprecedented number of arrivals and an increased number of people presenting with a range of significant complex medical conditions".

"We look forward to working constructively with Dr Sanggaran to review these matters and to resolve his concerns," IHMS added.