Police believe offenders responsible for a recent series of rural mail thefts targeting North Canterbury residents are from the North Island.
More cases of stolen cheques have come to light and police believe some $18,000 may have been withdrawn from unsuspecting rural residents' bank accounts.
Detective Sergeant Rex Barnett, of the Rangiora CIB said cheques stolen from rural mail boxes had been altered and deposited in two bank accounts in the Coromandel area.
Police began investigating the thefts last month after a Swannanoa woman who sent a $100 cheque as a donation to a local charity was shocked to find her bank balance had been debited $10,067.
She had left an envelope containing the cheque in her rural mail box on Tram Rd and put the red flag up indicating there was mail to be collected.
Detective Sergeant Barnett said several other cases came to light as local residents received their bank statements and found discrepancies.
Six fraudulently altered cheques had turned up involving amounts ranging from $1000 to $10,000.
"It appears (the scam) originated in the North Island. We think the offenders may have been down here at some stage. They've taken quite an involved course of action."
He said more than one offender appeared to be involved and the suspects were believed to be in the Coromandel area. Inquiries were continuing.
"Some cheques have gone into two different bank accounts," Detective Sergeant Barnett said.
The cheques had been "washed," with new amounts and a different payee added.
Offenders had then withdrawn various amounts from the accounts the cheques had been paid into.