Lorraine and Aaron Cohen, who spent years in a Malaysian jail for narcotics offences, are back behind bars.

Yesterday, Justice John Priestley jailed each of them for four years for drug offences.

The judge, sitting in the High Court at Auckland, told the 58-year-old mother she was a major force in pushing other lives down the slippery slope, which she had descended years ago.

"At the core of offending of this type lies misery, the blighting of lives and the destruction of human potential."

Justice Priestley told 35-year-old Aaron Cohen that he had had a lot to put up with in his life, on heroin by the age of 15 and spending 13 years in a foreign jail.

But the judge said that he had been willing to deal in a wide range of drugs to generate the cashflow to sustain his own drug use.

"In doing that, Mr Cohen, you were exposing others to the dreadful problems drugs have caused you, delaying the rehabilitation of those people and also playing a significant part in blighting their lives."

Telephone intercepts, the judge said, showed a cheerful acceptance by addicts of drug use being normal and acceptable.

Margaret Rogers, appearing for the Crown, quoted a Court of Appeal case where it was said that while the miserable victims of drugs deserved to be pitied, when they stooped to systematically spreading the contagion the courts were left with little room for the exercise of mercy.

Peter Kaye, appearing for Lorraine Cohen, told the judge that she suffered from cancer and had lymph nodes removed. Her prognosis was high-risk.

Mr Kaye said that rehabilitation was forlorn but imprisonment was an exercise in abject futility.

Passing sentence, Justice Priestley said she was entitled to compassion for her ill health and the tragedy of her life over the past 40 years. He gave her credit for her guilty pleas.

Christopher Comeskey, appearing for Aaron Cohen, said that his client was to be seen more as a "consultant" giving advice.

His dealing came about because people sought him out as a repository of information due to his notoriety.

Seeking a suspended prison term, Mr Comeskey said that Cohen's personal circumstances were unique as he had spent 13 years in an overseas prison and was subjected to a barbaric flogging.

The jurors had asked during their deliberations if they could recommend mercy but did not add any rider to their verdict.

Justice Priestley told Cohen he was being as merciful as the law allowed.

The judge said that his offending could not be blamed on his mother or his background and he had to take responsibility.

Lorraine Cohen had pleaded guilty to charges of possession of morphine sulphate for supply, conspiracy to supply the drug and conspiracy to supply methamphetamine.

Her son was found guilty of conspiracy to manufacture heroin, conspiracy to supply morphine sulphate, conspiring to supply methamphetamine, having the drug in his possession for supply, having methadone in his possession for supply, having cannabis, conspiring to import cannabis seeds, and offering to supply cannabis.