Jerry Collins wrote an emotional letter to former Campbell Live host John Campbell after the journalist visited him in a Japanese prison.
Collins was arrested in March 2013 for carrying a knife in a department store.
He later said it was a result of a misunderstanding with a gang.
Mr Campbell visited Collins in prison, with the former Hurricanes and All Blacks flanker writing a letter to the broadcaster last month.
"I'd just like to thank you for coming to see me while I was in jail in Japan," he wrote.
"You were the only journalist who came and though we couldn't physically speak through the glass, the sign language that day helped alleviate my family's fears and quell a lot of rumours surrounding the incident at the time."
Collins and his partner Alana Madill died when the car they were travelling in was hit by a bus on a French motorway on Friday.
Their four-month-old daughter Ayla is in a critical condition in hospital.
Mr Campbell left TV3 last month after his show was axed by management.