Sydney  - A German doctor with a Down's syndrome child has won his fight to stay in Australia.

Bernhard Moeller, on a temporary visa since arriving in 2005 to work at a small hospital in rural Victoria, had been denied permanent residency because the Immigration Department deemed the public cost of medical treatment for 13-year-old son, Lukas, too high.

On Wednesday, just hours after Moeller lost his appeal before the Migration Review Tribunal, Immigration Minister Chris Evans interceded and used his discretionary powers to grant permanent residency.

"It was clear to me that Dr Moeller and his family are making a very valuable contribution to their local community," Evans told Parliament. "Dr Moeller is providing a much-needed service in the area, the family have integrated very well and they have substantial community support."

Moeller and his wife whipped up public sympathy for their case with even cabinet colleagues urging Evans to intercede out of human compassion.

Sydney University law professor Ron McCallum, who earlier this month was appointed to the UN Committee for the Convention on the Rights of Persons with Disabilities, described the initial decision as "outrageous" and demanded ministerial intervention.

"It's outrageous a family is denied immigration because of a disability in their family," McCallum said. "We signed this convention to give disabled people the same rights as the rest of the community."

Down's syndrome is a congenital chromosomal abnormality that shows up in varying degrees of mental disability.

The department's initial ruling was that the potential cost of care for Lukas would be several hundred thousand Australian dollars (a couple hundred thousand US dollars) over his lifetime). Moeller disputed that argument, saying he stood ready to pay any extra costs.

On average, 1,500 visa applications are turned down each year because the Immigration Department considers the health costs incurred in granting permanent residency would be too high. In some of those cases, the minister has used discretionary powers to overturn the decision. (dpa)