A gifted teenage swimmer has won a landmark legal battle after his parents tried to block his dream of representing New Zealand because they disapproved of his Olympic gold medallist girlfriend.

Justin Wright, 17, struck up a romantic relationship with United States Olympic champion Rhi Jeffrey, 24, after meeting at the West Auckland Aquatic Club.

Jeffrey, who won gold at Athens in 2004, moved to Auckland in a bid to qualify for next year's London Games under her Kiwi coach David Wright.

Justin's parents Paul and Sandy, the former club secretary, tried to break up the relationship and bombarded club members with emails, demanding their coach intervene.

The correspondence became so abusive that David Wright (who is no relation) hired a lawyer to ask that the emails stop.

In one email, Sandy claimed the American had "stolen [Justin] from the cradle".

She and her husband withdrew their consent for Justin to compete at Swimming New Zealand events, destroying his chances of qualifying for the Swimming World Cup in November.

In what is believed to be a legal first, Justin won court permission this week to be a member of Swimming New Zealand against his parents' wishes.

The Westlake Boys' High School student, who turns 18 in three months, said he was "annoyed" his parents had tried to prevent him from competing.

"I couldn't believe they had done that," he said. "But now that we have been through the court and I can swim I am pretty happy."

He was not sure if he could mend his relationship with his parents, but said he would not give up Rhi.

"I'm not sure how they feel now, I tried," he said. "Things are good with Rhi, really good."

Jeffrey, who won gold with the US freestyle relay team, said she was doing what she could to support Justin's training.

"It was unfortunate that it came to this. I can understand their reservations about the age difference but I see myself as a big kid anyway."

Jeffrey said she had never met Justin's parents.

"It would be one thing if they had made their minds up after they met me," she said. "I am a very abrasive in-your-face kind of person and a lot of people don't appreciate that but those people don't know me from the next person on the street."

The couple are living together in Jeffrey's Titirangi apartment.

Their coach Wright said Justin's swimming had gone from strength to strength since his relationship with Rhi.

"She is a very hard trainer and she makes him go to every training session she goes to. He has improved his personal best time in the 50-metre butterfly by 1.5 seconds, which is huge," he said.

According to court documents, Swimming New Zealand terminated Justin's membership as he was under 18 years old and no longer had the permission of his parents.

The judgment was rushed through so Justin could compete at the Auckland Winter Championships yesterday.

Justin said he needed to lower his personal best to qualify for World Cup events in Asia.

He told the court he had swum approximately 3500km in training and attended 100 gym sessions this year.

"Swimming means a lot to me," he said in written evidence. "I have dedicated a lot of my life to being able to participate in these events. All of this energy and effort would be wasted if I am not able to be a member of SNZ until my 18th birthday."

"My parents objected to my relationship with Rhi from the beginning. This is largely because she is older than me, 24 years of age."

The court heard his mother, a former club secretary, had launched an email campaign in an attempt to break the couple up. On March 12 she sent an email to David Wright asking him to intervene in the relationship, which he refused to do.

Justin said: "My mother's reply was to issue me with a set of options; this left me with little choice but to move out of my parent's home."

West Auckland Aquatics swim team president Claudia Hill warned Sandy Wright to stop emailing club members.

Hill wrote: "From a personal perspective I can completely understand that you are upset at your son being involved with an older woman but this is a family matter and not for others to intervene.

"Use of the club email address book to distribute a personal grievance to our members is completely unacceptable and highly inappropriate," she added. "Any further correspondence in this vein to club members will not be tolerated."

Following a barrage of emails, David Wright asked his lawyer John Anderson to write to Justin's parents.

"Many of your comments are clearly defamatory of Mr Wright and/or constitute harassment of him," the letter warned.

Justin's parents then refused to pay his club fees - so Justin signed his own membership and had his fees paid by a group of West Auckland Aquatic parents, he said.

Judge Graham Hubble granted permission for Justin to enter into the contract with Swimming New Zealand in the Auckland District Court on Thursday.

The application was not opposed.

Justin's father Paul, a swimming official, denied he withdrew his consent because of Justin's relationship with Jeffrey.

He claimed it was because his son had broken house rules.

"There is a lot of bad blood at the moment.

"We wanted him to come to us with a financial plan of how he was going to support himself to swim competitively. And he didn't do that. We pay for his schooling but we couldn't pay for his swimming, which we see as an extra curricular thing."