Stanley Hou, 36, was charged after police discovered a commercial-grade drug lab set up inside a Hume warehouse after receiving reports of hazardous materials and fumes coming from the building in August 2014.

Police who raided the Sheppard Street building immediately noticed a strong chemical smell and seized glass beakers, drums of precursor chemicals, a heating element and laboratory equipment.

They also examined a laptop that belonged to Hou and discovered internet searches for phrases including "how to grow MDMA crystals" and "lab supply".

Hou last year pleaded not guilty to drugs charges and was to go on trial in the ACT Supreme Court in March.

But that trial was abandoned when he pleaded guilty to manufacturing MDMA, commonly known as ecstasy, drug trafficking and possessing a large commercial quantity of a controlled precursor.

He has been behind bars since and was in court for sentencing in front of Acting Justice David Robinson on Friday.

A pre-sentence report author told the court Hou had started gambling through poker machines and casinos when he was 18, but his habit had escalated to betting on sports and horse racing through mobile phone apps.

Hou claimed he set up the drug lab out of "desperation and fear" under an arrangement to service gambling debts of more than $60,000, after associates of a bookie he used had made attempts to get the outstanding money back, she said.

From the witness box, Hou's aunt said his family had moved to the ACT from Sydney after his father was bashed to death, in an attack she understood was related to gambling debts, at Kings Cross one Christmas Eve in the mid-1980s.

His aunt later became aware of Hou's gambling habit and had lent her nephew about $50,000 over the course of one year to help him clear his debts, about $20,000 of which hadn't been repaid.

She recalled her shock when she learnt of the charges against Hou, who she said had always been gentle, softly-spoken, hard-working and a patient father to his two daughters.

But Acting Justice Robinson said he had difficulty finding the link between Hou's gambling and the drug offences.

Defence barrister Michael Kukulies-Smith pointed out the report author said Hou's gambling was the number one risk factor to his likelihood of reoffending, which he argued showed a link between his client's habit and crimes.

But the judge said the report author's evidence was an opinion, which had been based on limited information about his offending that Hou had told her.

The Crown, represented by prosecutor Sara Gul, argued there was no relationship between the gambling and drug offences.

Ms Gul said the sophistication of the drug lab set-up, the fact Hou was the principal offender, the amount of pre-meditation and planning involved, and a strong need for general deterrence meant a term of full-time imprisonment was the only option.

Mr Kukulies-Smith said the fact the three offences were inter-related meant any sentences imposed should be wholly concurrent.

Acting Justice Robinson is expected to hand down his sentence next month.