Former All Black Dean Kenny is fighting the Immigration Service because it refuses to let his Welsh-born wife of nine years remain in New Zealand.

Mr Kenny, an All Black in 1986 who played 110 games for Otago during the 1980s, says he is insulted the service labels his marriage a sham.

The former halfback returned to New Zealand in December with wife Amanda and their two young daughters but received a letter on June 2 saying it was suspected the marriage was not genuine.

As a result, his wife was not granted residency.

Amid fears she would be deported immediately, the Kennys gained an extra 30 days to remedy the situation.

Mr Kenny said he was "fuming" at the Immigration Service's attitude. "They've told us they want to make sure it's not a marriage of convenience. We've been married nine years," he said.

"If that was the case, I'd have bought her over here and ditched her after two years."

The couple have been asked to provide proof of their marriage's authenticity - for the third time.

That includes another residency application plus photos of them together, photos of their children together, copies of love letters, proof of shared income and bank accounts and evidence of family or public recognition of the relationship.

However, they were informed their latest application could take a year to process.

It is an anxious time for the couple and their children, Nia, 8, and Brooke, 4.

"It's quite disturbing really. We gave them everything they asked for and they came back wanting all sorts of other proof. Now, we face a year's wait?

"I had to tell my eldest girl that we might be appearing on TV and why. It's very stressful for them to be facing living without mummy."

NZ First MP Dail Jones, who raised the case in Parliament this week, said the Kennys' ordeal was a farce and an absolute disgrace.

Immigration Minister Paul Swain said he would look into it.