Police have cracked a methamphetamine ring they say was being run out of Manawatu Prison.

Photo: RNZ / Simon Williams

Six people have appeared in Palmerston North District Court today on drug supply and firearm charges.

Detectives acted on information that an inmate had been arranging for the sale and distribution of methamphetamine via people outside the jail.

Detective Senior Sergeant Simon Harrison said the arrests should reassure people that preventing methamphetamine supply was a high priority for police.

The arrests showed that, when it came to investigating the selling of the drug, nowhere and no-one was off-limits to them, he said.