Gardner - a New Zealand citizen who lives in Richmond, northwest of Sydney - could face execution by firing squad if he is charged and convicted.
"The Consul-General has visited Mr Gardner in the detention centre to provide consular advice and check on his well-being. He remains in custody and has legal representation," a Ministry of Foreign Affairs and Trade (Mfat) spokesman in New Zealand said.
It is understood the Gardner family has been advised by lawyers not to comment.
New Zealand officials have denied behind-the-scenes diplomacy and lobbying by Australian officials was behind Ms Davis' release.
Davis reportedly met Gardner two weeks before their arrest on the dating app Tinder. Photo / Supplied
The Mfat spokesman said yesterday the decision to release Ms Davis was China's alone, and was not dictated by which government had lobbied Chinese officials harder.
"We understand the decision to release Ms Davis rested solely with Chinese authorities. The Australian Government has advised that no negotiations were held to secure Ms Davis' release, neither by consular officials nor by Foreign Minister Julie Bishop."
The Mfat spokesman said the ministry could not comment further on the ongoing investigation "or interfere in the judicial proceedings of another country".
Ms Davis was allowed to walk free by Chinese officials after it emerged the methamphetamine was found in checked-in luggage and Ms Davis had only carry-on luggage on the international flight.
Friends describe shock at allegations
Gardner's former boss yesterday said he was shocked by the allegations and described the accusations as out of character.
Gardner worked for Michael Kulakovski's building company in Richmond as an apprentice.
"He's not a bad person. He's a hard worker. He gave his 100 per cent all the time with me. He's a very passionate, loyal guy," Mr Kulakovski said.
Friends of both Mr Gardner and Ms Davis have taken to Facebook in recent days to express their shock at the allegations.
"I grew up with Pete, know (Kalynda) through mutual friends. Either one of them wouldn't just go and do this," one wrote. Another said: "I'm seriously speechless."
Ms Davis, the daughter of an esteemed former cop, is believed to have met Gardner on dating app Tinder before the pair's departure.
Kalynda Davis spirited away
Hiding beneath a grey jacket, Ms Davis was spirited away from her parents' Glenmore Park home in Sydney yesterday following her return from China.
While the 22-year-old remained tight-lipped over her Chinese ordeal, father Larry revealed he collapsed with relief when he laid eyes on his daughter.
"She didn't know that I was coming either. She kept saying 'I'm sorry dad, I didn't do it, I didn't do it, I didn't do it'," Mr Davis told a local Penrith newspaper.
"When we hit the tarmac in Sydney, we both just cried.
"She said that she can't understand how she can thank the people who saved her life but I said to her, 'no-one saved your life, you saved your life because of your actions, people just helped to get you back home'."
Earlier, the Davis' next-door neighbour passed a large suitcase over the fence and to a woman in the backyard of the home.
New South Wales police last night confirmed they were not conducting inquiries, indicating it would remain a matter for the Australian Federal Police.
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- Daily Telegraph Australia, NZME. News Service
