"There is no question that a transnational organised crime cartel is involved. They have tentacles, and the police say they have made many arrests," he said from Denpasar.
"The elements of a sophisticated human trafficking operation are easily made out - deception and recruitment, purpose of exploitation - the implications of this case are global and already raise serious jurisprudential issues.
"Sadly it may be that numerous other people may have been tortured and executed," he said.
"Our legal research team is locating similar cases and I have been contacted by families of other prisoners with grave concerns."
He has been told by Indonesian police that the woman de Malmanche had been in an internet relationship with has been arrested in Jakarta.
"We have a lawyer there now investigating," Mr Tuck said.
The specialist human rights lawyer has also met police investigators and the head of the Narcotics Investigation Unit as well as Indonesian defence counsel.
Police had confirmed that investigations into the drug ring de Malmanche has been linked to continue in Africa, Hong Kong, China and Indonesia.
"It is abundantly clear that Tony has been caught up in a highly organised criminal group and through fraud and deception has been exploited," said Mr Tuck.
Tuck says despite de Malmanche's predicament, he was trying to stay positive. Photo / John Borren
He has met de Malmanche a number of times and the pair have been allowed access to the evidence and exhibits police will be presenting.
"I have spent many hours with Tony. At this stage I don't want to go into the details of the 'how' he got to where he is. Suffice to say we have a diverse team of lawyers and forensic people working on a raft of material in support of the defence.
"The police are investigating what they believe to be a sophisticated global network running mules or couriers. I need to emphasise the investigators are being professional and transparent. This is a very big deal over here.
"The Indonesian criminal justice system and the police are entitled to deal with Tony according to the law of the land - no question of that. Our job here is to support Tony and resource his defence as best we can, as I would for any client anywhere."
Mr Tuck is due to return to New Zealand on January 9 but will continue working on the case.
De Malmanche will soon be moved from Denpasar police station to the notorious Kerobokan Prison, and his trial is expected to begin in March.
Mr Tuck said the case would be heard one day a week for about 10 weeks, and then a decision would be given.
If a conviction were entered and de Malmanche wanted to appeal, it could take up to a year.
Mr Tuck said despite de Malmanche's predicament, the prisoner was trying to stay positive.
"He now finds himself in a situation which is literally life and death. Tony is doing it hard but still retaining a sense of Kiwi humour," he said.
"It would be fair to say he is in shock. It is a classic WTF (what the f***) type situation.
"Tony misses his boys and grandchildren terribly. He is holding it together, but it is clear that he is on the conveyor belt to trial.
"He has a strong Christian faith and he sends thanks to friends and family who he knows are praying for him in Wanganui and around the world."
After de Malmanche's arrest, his shocked family began to fundraise to help pay for a lawyer. More than $10,000 has been given and his son Shaun said he wanted to thank every person who has donated.
"We really miss him and we are blown away with the support so far," he said.
"We thank you all, New Zealand and abroad, from the bottom of our hearts. We will continue to stand by my dad through it all, until the end.
"We need your help, too, to bring my dad home."
