A 42-year-old Czech man has been sentenced to 17 years' jail for trying to smuggle 20kg of methamphetamine with a street value of up to $20 million through Auckland Airport last year.

Jiri Kupec arrived on a flight from Bangkok with his 69-year-old mother in May 2016, and was questioned and searched by Customs officers after being profiled as "high-risk" by Customs intelligence.

A baggage search located the meth hidden under false linings of their suitcases.

His mother was also arrested but charges were dropped, as the investigation did not show she had knowledge of the drugs and she was subsequently deported.

He was sentenced in the Manukau District Court today.

Customs investigations manager Bruce Berry said other than this amount being unusual for an air passenger and the largest ever meth seizure at a New Zealand airport, this case highlighted the work Customs did daily to identify high-risk passengers who could be potential drug couriers.

"This result reaffirms the value of Customs' intelligence using data and technology to identify those individuals that may pose a risk, which is then followed up by our frontline officers at the airport. The officer's searching skills have contributed to this result.

"While the concealment was relatively straightforward, it's using intelligence approaches to identify risk passengers that allow our officers to do the good work that they do. In this case, the passenger tried to disguise himself as a legitimate traveller, but we saw through that.

"Transnational syndicates don't care about the harm this drug causes in our communities, nor do they care about the drug couriers who end up facing the consequences. This man admitted he knew he was doing something illegal - and will now pay the price."