A drug dealing Kapiti Coast grandmother has been jailed for six years.

The Wellington District Court was told Pamela Ann Ranga, 63, a beneficiary, of Raumati Beach, whose only declared income was a benefit of $242 a week had almost $600,000 deposited into her bank accounts over the previous three years, the Dominion Post reported.

Ranga dealt morphine to heroin addicts and used the proceeds to fund a lavish lifestyle of gold watches, diamond rings and BMW cars, police told the court .

Yesterday she was convicted and sentenced to six years in prison on charges of possessing, supplying and conspiring to supply morphine sulphate.