Beckham appealed the conviction while the Solicitor General appealed against the length of the jail term on the grounds that considerations the sentencing judge made in reducing the sentence by five years no longer existed.
In a decision released this week the Court of Appeal dismissed Beckham's appeal, but granted the Crown appeal, quashing Beckham's jail term and replacing it with one of 18 years' imprisonment with a minimum non-parole period of nine years. Supplying methamphetamine - or P as it is also known - has a maximum penalty of life imprisonment.
Beckham's appeal was on two grounds - an alleged abuse of process by police and relating to the granting of three interception warrants obtained by police for electronic surveillance.
The Court of Appeal ruling found there was no abuse of process and that the interception warrants were properly issued.
The court said Beckham's lawyer had agreed that in the circumstances the Crown application to lift the jail term should be granted.
During his Auckland trial it was revealed Beckham was the kingpin of a methamphetamine syndicate. Detectives found $865,720 hidden in a vehicle at his home when Beckham was arrested in 2008. Beckham's assets and cash worth more than $10 million have been restrained. He was arrested after a six-month inquiry during which police tapped his cellphone and bugged his car.