Mr Clement said Operation Concord had received more than 150 calls and more than 260 relevant emails.
The deputy commissioner said he was grateful to members of the public who were helping authorities.
"We continue to urge the public to be vigilant and report anything suspicious, and we continue to appeal for anyone with information relevant to the enquiry to contact Police," he added.
Mr Clement would not say which people or specific parts of the country were relevant to the investigation.
A Massey University food safety expert earlier told NZME. News Service only a few people had authorised access to the 1080 poison most likely used in the blackmail letters.
Authorities have repeatedly refused to elaborate on the likely source of the 1080 - for example, whether it came from a laboratory, a stolen 1080 stockpile, or pellets picked up in the bush.
Supermarket giant Foodstuffs, owner of Pak'nSave, Four Square and New World, said its stores were "maintaining heightened surveillance" around infant formula.
In big stores, this included non-stop CCTV monitoring of relevant shelves, signs advising customers of the threat, and the presence of "Infant Formula Milk Monitors."
These monitors watched products on shelves and offered advice to infant formula buyers on how to check for tampering.
Foodstuffs managing director Steve Anderson said in smaller New Worlds or Four Square stores where full CCTV coverage at shelf was not possible, other security measures were in place.In some cases, infant formula was moved to the front of check-out so staff could continually visually monitor the product, Mr Anderson said.
Security advice from police and Foodstuffs remained unchanged, despite a planned 1080 drop in the South Island.
Yesterday, the Department of Conservation told the Otago Daily Times it had not carried out any aerial 1080 drops since March 31.
A TBfree New Zealand spokesman said the group's last aerial 1080 drop was in the Buller region on March 31.
That would make TBfree's plans to begin a new poison drop around Wanaka the first to be carried out since the deadline, the Otago Daily Times added.
Anonymous letters sent to Fonterra and Federated Farmers in November said formula would be laced with 1080 if New Zealand didn't stop using the poison for pest control by the end of March.
Police launched Operation Concord in response.
WHO TO CONTACT
If you have any questions about what to feed your baby, call Plunketline 0800 933 922 or Healthline 0800 611 116
For more information go to foodprotection.govt.nz
The Ministry for Primary Industries (food safety issues): 0800 008 333
Advice for consumers: www.mpi. govt.nz (link is external)
Health Line: 0800 611 116
Plunket Line: 0800 933 922
Police say people are welcome to contact them anytime if they have information possibly of use to the investigation.
Police are appealing for the person or group behind the threat to make themselves known.
Police said anyone who might know of someone who has strong views on the 1080 issue and made threats, or has discussed how to access supplies of 1080, should contact police.
The Operation Concord inquiry team phone number is 0800 723 665 and their email address is concord@police.govt.nz
To contact the anonymous Crimestoppers organisation call 0800 555 111 or visit www.crimestoppers-nz.org
