"I've got over that initial shock you get at first, but you've got to take it as it comes. We're managing, we're pulling together. We're still a close family. The Chinese are treating him okay."
Gardner said his son had never been in serious trouble before, but didn't want to speculate on his guilt.
"I don't know if he's innocent. She obviously was innocent because the police wouldn't have let her go if they couldn't pin it on her. There's probably more to the story but the embassy know and the lawyers know."
He compared the attention the case was getting to another infamous drug smuggling case. "It's the whole Schapelle Corby thing, you know, pretty blonde girl."
Sydney's Daily Telegraph reported Australian consular officials spent more than three weeks in China in intense negotiations to prove Davis had no knowledge of the drugs when she and Peter, 25, were arrested at a Guangzhou airport last month.
Her parents Larry - a former police officer - and Jenny Davis said they would "continue to pray for Peter and [his] family. You are always in our thoughts."
Russell Gardner - a former Royal New Zealand Air Force engineer - said he had hired a Chinese lawyer and the family were anxiously awaiting the outcome of the Chinese investigation.
He said the total Peter was alleged to have been carrying of 75kg of meth, worth $86.3 million, was "someone's wild guess".
"I don't know where they got that figure from because [even the] lawyers don't know yet. The police haven't released it, the investigation is still going. When he gets charged we'll know then I suppose. But you're not allowed to carry more than 20kg in luggage anyway."
Gardner, originally from Hawke's Bay, said Peter was young when he and his ex-wife Sandy moved their family to Sydney in the late 1990s.
Russell now works at Australian Aerospace, on a Royal Australian Air Force base in Richmond, west Sydney.
Peter's mother, Sandy Cornelius, returned to New Zealand several years ago and lives in Kaiapoi, North Canterbury. She could not be reached for comment.
Russell said Peter was still close to his New Zealand family and had visited his mother a few months ago.
In October, New Zealand police opened an office in Guangzhou to combat the importation into New Zealand of precursors used in the manufacture of methamphetamine.