Notes left at the homes of Oamaru residents promising gifts if the receivers call a phone number have prompted a warning from Age Concern Waitaki.
Office administrator Vivienne Gamble said there were several concerns about the new sticker, including the ethics of it and who was being targeted.
Ms Gamble said the way the note was constructed was worrying.
The note reads "Please Call Regarding A Promotional Package We Have On Hold For You''.
Below that is a sticker with an 03 number on it.
Further down, the note states that it is a promotion to obtain business and receiving the "gift'' is subject to the HAP company's rules, which were obtainable on request.
The Otago Daily Times was unable to obtain the rules.
Ms Gamble believed the note was constructed to make people think they had missed a legitimate postal delivery and there was a package that someone was trying to send to them.
She said the note amounted to "cold calling sales - trying to get you to make contact''.
She said it was known the company had salespeople roaming Oamaru's streets in pairs.
Over the past few years, there have been regular news reports around New Zealand detailing the activities of salespeople doing the rounds of towns and cities offering vacuum cleaners costing at least $3000, drawing advice from consumer groups to avoid doing business with them.
To help combat pushy door-to door salespeople, society watch dog Consumer NZ launched a sticker campaign in 2014.
To obtain one of their "do not knock'' stickers, phone Consumer New Zealand on 0800 CONSUMER or contact your nearest Citizens Advice Bureau.
