By day, advertising executive Reece Shadbolt worked hard to convince New Zealand women that Toffee Pops were all they needed for a satisfied sex life.

But by night, the man behind the Carlos Spencer chocolate biscuit ads demanded far more to satisfy his own sexual appetite.

Friends and workmates had little idea that the Auckland advertising executive, dividing his days between the golf course and the office, had another life with prostitutes he met through gentlemen's clubs.

That was until he cheated on one escort, Dionne Liza Neale, with another. So Neale visited him in his Parnell apartment and stabbed him nine times with a carving knife.

"It was like stabbing a roast," she told police afterwards.

Long after the killing, her mother says, Neale continued to wear the engagement ring that Shadbolt gave her. When she was convicted of his murder on Friday Shadbolt's father applauded the jury's "very justifiable" verdict. Shadbolt's mum went home to celebrate the conviction and her 60th birthday with a bottle of Moet.

But now details are emerging of Shadbolt and Neale's tempestuous relationship that are likely to be used in an appeal against that conviction.

Shadbolt had been one of the popular kids at Rosehill College in Papakura. "He was a sporty guy, a real friendly fella," said classmate Lilian Puru. "He never got into trouble. He wasn't that kind of guy."

He went on to work at ad agencies including McCann Erickson, Grey Worldwide and Hyde Group, as studio manager. A colleague there remembers a talented creative with a wife and two kids. But during that year the colleague believed his marriage started to fall apart.

At the same time, he registered his own company - Kaboom - but that survived only three years.

During those three years, he met Neale at Mustang's Gentleman's Club on the North Shore, where the 34-year-old worked as an escort.

A tall, attractive brunette with children, Neale had been a hairdresser until financial difficulties forced her into prostitution. A $300 rates bill on her Helensville home was the final straw.

After meeting in 2004, the two formed a relationship that appears to have gone beyond sex and money: he moved in with her, then they sold the house to invest in Shadbolt's Albany car business together.

Carol Taylor, Neale's mother, describes Shadbolt as "charming".

"He said he absolutely loved Dionne; she was the most beautiful girl he had come across."

But there was a darker side: she said he had a voracious sexual appetite, that he always had pornography on his laptop.

"They met on the job - he was her client," Taylor says. "He liked his golf. He liked the good things in life, flash clothes and cars."

"But, you know," she adds, "Reece was a sex addict. Dionne would do anything for him - she degraded herself in other words.

"He talked her back into working. She didn't want to do it in the first place, she hated it."

But when the business collapsed, the two were left with little and they broke up.

Shadbolt got a job at the Parnell office of JWT, a multinational advertising company. The two tried again at a relationship in 2006, and in February 2007 Neale helped Shadbolt move into his new apartment, just a few blocks from his office.

A day or two later, Neale - who was back working at a gentlemen's club - visited Shadbolt for dinner.

Crown prosecutors said she plied him with alcohol, then confronted him about visits to inner-city brothels. He admitted to visiting massage parlours, and to a sex romp with a Scottish prostitute.

The couple slept together again - but when Neale left, she was furious. She was alleged by police to have scratched the words "cheater" and "whore addict" into the paintwork of his car.

On the morning of Waitangi Day, 2007, Neale paid a surprise visit to the Parnell apartment. She was carrying a large knife in her handbag. Shadbolt was about to leave for a game of golf, but first he poured Neale a cup of tea.

Neale refused to have sex with him again, her defence lawyer told the High Court in Auckland this week. Shadbolt looked down at her and said: "Stupid whore, I can get it anywhere."

He walked out of the room, and went to the bathroom for a shower. Neale grabbed the knife and followed him in.

Here, the stories diverge. According to police, she plunged the knife into Shadbolt's chest, penetrating his heart and lungs. That wound alone would have been fatal, but she stabbed him eight more times in the back, the throat, the torso, shoulder and arms.

According to Neale's defence, Shadbolt came running at her with his arms out, screaming obscenities, but slipped on the wet floor and fell on Neale's knife. Neale, now 39, has directed her defence lawyer, Barry Hart, to appeal her conviction.

"She didn't mean to kill him," her mother says. "She just wanted to hurt him. She said if she could go back and change everything she would. She would have walked away from Reece at the beginning. Dionne wants people to know she wasn't just a prostitute."