Questionable door knocking techniques used by a company in Christchurch has worried the director enough to come to town.

Residents in the eastern suburbs have accused sales reps representing home alarm company Vivint of intimidating and unprofessional behaviour. And it isn't the first time: TVNZ's Fair Go unearthed the company using similar behaviour over a year ago in Auckland.

Both the Commerce Commission and Consumer New Zealand are concerned about the company's tactics.

A number of New Brighton residents contacted Newstalk ZB with their concerns: Some residents said they've found salespeople snooping around their property, while other residents have been asked personal questions.

Age Concern CEO Simon Templeton relates that it's concerning for elderly people in particular, who tend to be targeted by door-to-door salesmen.

"If someone is living alone and is lonely and feeling a bit isolated, having someone come into their home and talk to them for a few hours is seen as a good thing."

Templeton advises residents to politely decline the offer, but if they still are interested, they can always do their own homework.

But Vivint New Zealand director Marsden Hulme said they don't encourage pushy sales techniques and if it's true, there would be consequences.

"I take this seriously enough to be flying to Christchurch myself to investigate further. I do trust my team but it is very important that we maintain a professional image."

Hulme insists the complaints might need to be looked at objectively.

"If we take some of these comments in isolation there can be any number of interpretation but I certainly take on board concerns about entering properties."

"The last thing I would call us is a rip off."

New Brighton resident Jessica Lunsford signed on to the company, which installed the alarm system in her home straight away - but she's pretty happy with how she was approached.

"I actually thought the man was totally professional and very pleasant. I didn't find him pushy whatsoever. I just thought he was a great salesperson really."