An athletic man, Mr Hill liked to cycle, fish, and walk, and was a swimmer in his teens. He had plenty of friends, many of whom had called to ask how they could help.
Mr Hill snr said a friend told the family he used to mountain bike in Lismore Forrest, so they visited the area on the weekend and met cyclists who said they would keep an eye out for him.
The family also visited locals in the area and asked them to keep a look out.
None of their searches turned up anything.
"We're desperate for information, it's a very worrying time, sleepless nights, we just need one lead. It's the sleepless nights that get you, you wake up every five minutes and it's there again," Mr Hill snr said.
His son is tall, and someone must have seen something, he said.
If anyone had seen, or saw, his bike, a Milazo mountain bike half yellow at the front and half black at the back, they should get in touch with police, he said.
Mr Hill snr was sure something must have happened to his son.
"He would always keep in touch with us. He absolutely adores his kids," he said.
Mr Hill had suffered from some depression in the past, but they didn't know if that had led to his disappearance.
"He might have gone on his ride and had an accident."
Looking after the missing man's wife and three children, aged 10, 6 and 1, was the family's focus at the moment, Mr Hill snr said.
Mr Hill's brother Mike and his wife Tiana had taken time off work and travelled from Auckland to be with the family, but were at a loss as to what to do next, other than appeal to the public for information.
Mr Hill is described as Caucasian, of athletic build, 189cm tall, with short blond hair.
He is believed to be wearing a blue polo shirt, black parka, a small black backpack, and a dark cycle helmet.