Concerned parents have demanded the option of single measles jabs free on the NHS.

This comes after reports of more research showing a link between autism and the controversial MMR triple vaccine.

Autism Research Campaign for Health cites a study by John O'Leary of Trinity College, Dublin, which found the strain of measles from the MMR vaccine in the guts of 12 autistic children who had received the triple injection.

The group says the research, reported in The Sunday Telegraph, raises "important questions" about the safety of MMR, and calls on ministers to drop all publicity that claims MMR to be "indisputably safe".

The Government must commission a new study to investigate any links between MMR, autism and bowel disease, and in the mean time offer single jabs on the NHS to those parents who want them, ARCH says.

Martin Hewitt, one of the campaign organisers, said: "The Department of Health has got to take far more seriously the possibility that the MMR may not be safe for all children. The MMR appears to be safe for the majority, but not for a small group of susceptible children."

"The government must now act to safeguard children whose parents ask whether to vaccinate their children."

Research reviewing previous studies into MMR safety published last week was welcomed by the DoH, which said the findings confirmed earlier conclusions that there was no link between MMR and autism or inflammatory bowel disease.