Befriending a 62-year-old woman, Shane Harwood told a litany of lies to gain more than $34,000 fraudulently from her to pay for drugs.
The 33-year-old Masterton man pleaded guilty to a representative charge of fraud when he appeared before Judge Bruce Davidson in Masterton District Court on Monday.
Police prosecutor Sergeant Jodie Lawrence said Harwood befriended the elderly woman in 2011 and by January 2012 had moved into her house.
During the next 18 months he told a range of lies including that his grandmother had died, Ms Lawrence said.
He also conned a friend into pretending she was his mother to confirm he'd be receiving a $90,000 inheritance from his grandmother's estate so he could pay money back, she said.
In total, he conned the woman out of $34,586 between December 1, 2011 and June 2, 2013.
"There was no dead grandmother and no inheritance ... he decided to tell lies."
When spoken to about the fraud, Harwood told police he "needed the money for drugs", the prosecutor said.
Defence lawyer Peter Stevens said his client had relapsed at the time and was now seeking rehabilitation for his drug addiction.
Judge Davidson convicted Harwood on the charge and ordered a drug and alcohol assessment as part of the pre-sentence report to help the court at sentencing on June 23.