Couples who cannot have children are stunned and angry New Zealand's child-protection agency has pulled out of helping to arrange adoptions from Russia.

One Auckland couple thought they were the victims of a "sickening joke" when they received a call out of the blue from the Child, Youth and Family Services on Tuesday night.

They soon realised the woman from the adoption unit was deadly serious - she told them their soon-to-be-completed adoption of two Russian children was off.

The couple were even more angry and confused when they heard a different story yesterday - that because the service had already approved them and paperwork was already in Russia, the adoption might go ahead - but they do not know for sure and cannot find out.

The couple, who are in their 40s, are among at least 30 families who received sudden calls from the department on Tuesday, some quite late into the evening, telling them it was ending its involvement in adoptions from Russia.

The department said that country's laws were no longer compatible with the Hague Convention, which sets standards for international adoption.

It said it sympathised with couples and accepted that the news would be traumatic. It defended the telephone calls, saying couples had to be told before the media.

Acting national adoptions manager Beth Nelson said that a Crown Law Office opinion indicated that the service would breach New Zealand's international obligations if the adoptions continued.

The organisation would work with the Russian Government to develop a Hague-based arrangement "as soon as possible."

The Auckland couple were devastated. They said they had been excited about going to Russia within the next two months, which they saw as their only hope to be parents, since the woman cannot have children for medical reasons.

As an older Pakeha couple they had little chance of adopting a New Zealand child and said the processes in other countries could take years.

They were also offering a better life to children who had no future, the man said.

"These kids get turned out onto the street when they are 14 or 15 and boys would go into the Army and the girls end up on the street as prostitutes or whatever."

Wendy Hawke, from Intercountry Adoption NZ, said 439 Russian orphans were now living here.

The New Zealand move was "bizarre" since adoptions continued from countries such as China, which had not signed the Hague Convention.

But a Child, Youth and Family spokesman from the service said NZ had bilateral agreements with countries such as China which were compatible with the convention.