The Salvation Army's gambling addiction support service is worried about the increased number of online gambling sites.
The head of the organisation's gambling services division, Oasis, said it had been noticeable since the nationwide lockdown came into force.
Lisa Campbell said the rise in the number of unregulated overseas online gambling websites had coincided with the closure of pokie venues and casinos, and online availability of New Zealand Lotto and TAB services.
Online gambling companies were now advertising on social media, possibly because they saw people in isolation as a captive audience, Campbell said.
The ads for overseas gambling websites were cropping up frequently when she was on Facebook in a private capacity, she said.
She was concerned that the tailored nature of how social media advertising worked, meant that others, including at-risk gamblers, were getting the same ads.
"I'm concerned they're using this opportunity to bring people into online gambling now, which is pretty awful to see that happening.
"I am sure they see social isolation as a great opportunity to expand business without any thought for the additional harm this could cause, further exacerbating the financial and mental harm on people already."
Oasis was now compiling information on online blocking tools that people can use to block internet gambling sites, Campbell said.
"We have heard from some clients who say they are really concerned about how they will cope, both financially and practically, at home with family or alone during the lockdown period, and are feeling very anxious, and some have asked for more support than normal."
Campbell said similar advertising was apparent before the lockdown but she was now seeing it more frequently.
Lotto and TAB were the only legal online providers of gambling, she said.
"They have said they're stopping advertising around the scratchies and other products during this time, so they're only advertising Lotto.
"The bigger concern is the overseas gambling websites where there's no regulation, which are potentially the biggest problem for us."
The Salvation Army was also encouraging anyone needing support through drug and alcohol addiction, to reach out if they needed help.
Spokesperson Lieutenant Colonel Lynette Hutson said they were concerned that people suffering from addictions may be feeling very alone at this time.
"The Salvation Army continues to support people online and over the phone. We want to make sure people have access to the help they need," she said.
There was also a danger that people could slide into heavy drinking when at home alone.
"We're here on the end of the phone for anyone who is feeling as if they may be getting into trouble with this, or other drug use," Hutson said.
Where to get help:
Bridge Residential services can be contacted by phone or email for referrals. For more information [www.salvationarmy.org.nz/Bridge visit their website], or phone 0800 53 00 00.
Supportive Accommodation/Transitional Housing services continue to operate across the country for those already in residence. Limited referrals may be considered, depending on availability of services. For more information, visit their website.
For direct access to Oasis services, [www.salvationarmy.org.nz/oasis see their website], or follow them on Facebook at OasisReducingGamblingHarm