A man was arrested last night for the murder of a New Zealand athlete, stabbed to death in Europe hours after competing in the age-group Triathlon World Championships.

Warwick John White was found bleeding heavily on a street, in Budapest, Hungary, early on Sunday, local time.

It is understood the 48-year-old was rushed to hospital but died on the way.

Police said Mr White was arguing with a woman he knew, when another man - who also knew the woman - approached them.

Police said this man stabbed Mr White.

It is understood he was stabbed more than once, and one of the wounds was to the heart.

Police issued photographs of three men who were arrested on the street where Mr White was found.

But only one of them - a 33-year-old known to police - has been charged with murder.

The woman has also been questioned by police, as a witness.

Known as "Waz", Mr White was a well-known triathlete and keen sportsman who travelled the world to compete.

He had lived in South America and Europe for the past eight years, but was planning to return to New Zealand this year to climb Mt Cook.

He was representing Ecuador at the Triathlon ITU World Championships in the 45-49 age group.

He finished 38th in the men's sprint event.

Mr White's family - who live in Wellington, Christchurch and Levin - last night described him as adventurous and loving.

Son-in-law Dylan Thomsen said his father-in-law had a "larger-than-life" attitude.

"He was much loved and he was a very loving man. He was a really larger-than-life type of character - you can see from the many things he achieved."

Mr Thomsen said it had been hard to hear how his father-in-law had died.

"People can obviously imagine what it felt like," he said. "The focus of the family is to get Warwick home ... we will miss him dearly."

Mr White travelled extensively, setting up language schools, adventure programmes, and developing property.

Mr Thomsen said Mr White had decided to represent Ecuador in his sport because he had lived in South America for several years.

Triathlon NZ chief executive Dave Beech also paid tribute to Mr White.

Speaking to the Herald from London last night, he said the killing was an "absolute tragedy for his family and for sport".

"I send my condolences to the family. What we understand is that he competed in his age group Saturday morning and then was stabbed while out in the Budapest central city," Mr Beech said. "It's absolutely awful that it has happened at an event like this."

Before leaving New Zealand, Mr White spent about 15 years teaching at Rongotai and Onslow Colleges in Wellington, and at Makoura College in the Wairarapa.

He also worked as an instructor at the Central Institute of Technology, now known as the Wellington Institute of Technology.

He also ran adventure tourism businesses, owning the Big Coast adventure race.

More than 4000 athletes competed at the world championships in Budapest, including top Kiwis Kris Gemmell, Martin van Barneveld and Andrea Hewitt.

The Budapest event was the seventh and final stage of the world championships.

Gemmell crashed out of his race during the cycling stage. World No 2 Hewitt was 22nd.

Two-time Olympic medallist Bevan Docherty was to have competed in Hungary, but a form slump cost him any chance of winning the overall championship and he pulled out.