Mental health incidents, fraud and domestic violence have shot up during lockdown, but other crime is down.

Police recorded 55 percent more mental health events, and 13 percent more family harm investigations in August and September, than in the same months in 2019, pre-pandemic.

There was also a 40 percent increase in fraud, deception and related offences, when comparing those periods.

Other crimes, like homicides, theft, and drug and traffic offences fell markedly, between August and September 2019 and those months last year, and this year.

Robbery, sexual assault and break-ins showed a downward trend over that time.

Lockdown has sparked a deluge of mental health callouts to police.

Police recorded nearly six thousand mental health occurrences August in September, which includes six weeks of Covid restrictions.

That's up 55 percent on the same period in 2019, before the pandemic, and is part of a growing trend.

Former police lead crisis negotiator Lance Burdett said we need certainty in our lives by focussing on what we can control, like food, sleep, and shelter.

He said people should change some things around in their house and, "fix one thing a day".

Anyone who needs to talk to a counsellor can call or text 1737 for free, anytime.

There's also been an increase in domestic violence during lockdown.

There were 28-and-a-half thousand police investigations into family harm in August and September this year, up 13 percent on the same period in 2019.

Assistant police commissioner Bruce O'Brien said there was a reduction in overall reported crime but Covid restrictions can, "amplify daily stresses", like financial or childcare issues.

He said when people are stuck in restrictions, that can, "play out in needing police to come and intervene".

O'Brien said there was an increase at the start of lockdown, but it's moving back to normal demand.

He said "anyone who's a victim of family harm or suspect someone else is, should call police immediately so they can support that whanau".

O'Brien said increases in mental health and family harm callouts were expected due to extra financial pressures and less social contact during lockdown.

However, he's confident as the country progresses into the new Covid system, we'll see things return to the normal demand.

On the family harm data, Women's Refuge CEO Ang Jury said, "those numbers are unacceptably high, and a huge number of whanau are being impacted".

However, she said it's a very blunt number and we need to know what's underneath it.

She's interested in what the investigations were for, because "refuges around the country saw little, if any, increase in service demand".

Jury said during the first lockdown it was, "so much more difficult to reach out for help", and the organisation "put various strategies in place to try and meet that".

However, she said there were only small spikes in demand when restrictions were eased.

Jury said the primary reason for domestic violence against a partner is control, and that's being exercised by lockdown, which may explain why Women's Refuge didn't experience an upswing in demand.

But she said generally there's a, "significant history of violence in the home before police are called".

Jury said,"Very few people invite police around for a cup of tea - they do so because they're scared of what might happen, so these are potentially quite serious."

She said more resources need to be put into domestic violence prevention.

Jury said prevention needs to start in the education system, and "services for people using, or thinking about using, violence needs to be beefed up".

She said, "It's an area of our service delivery model in the family violence space that's really not well developed and is crying out for more."

Burdett isn't surprised tensions have been boiling over in the home during lockdown.

He said Covid restrictions mean people have been confined to those they're living with, which causes friction, and many people have money issues.

And he said on a psychological level, we "look for a safe road ahead" but that's hard to find in this country, or globally.

Burdett said there's so much uncertainty around us, the brain goes into, "a mild fight or flight" response.

More Kiwis have been sucked in by fraudsters during lockdown.

Police data shows there were four thousand-600 reports of fraud, deception and related offences in August and September this year, mostly under Covid-19 restrictions.

This year's figure was 40 percent higher than the same months of 2019, before the pandemic.

NetSafe CEO Martin Cocker said the main increase has been online scams, about things like personal protective equipment, Covid misinformation and vaccines, as well as delivery of goods.

He said "The trick for scammers is to create a scam to that's close to what you're already expecting; therefore you're less likely to recognise it as a scam."

Cocker said, "prevention is the only cure when it comes to fraud", because once people get into a scam and lose their money, "it almost never gets recovered".

He said the instant someone thinks they might be caught up in a scam, they should call NetSafe to minimise any further losses or harm.

O'Brien said people are more vulnerable and on the internet more, during Covid restrictions.

And he said from an offenders' perspective there's an ability to take advantage of people spending more time online, and clicking into phishing emails.

O'Brien said people should have good internet security, "avoid clicking on unfamiliar links and never give out passwords or pin numbers".

He said, "your bank will never ask for that", so it's important people protect that information when they're dealing with calls about their finances.