Duncan Garner received death threats after he called for pitbulls to be banned.

Broadcaster Duncan Garner has revealed he received multiple death threats over his call to ban "horrible" pitbull dogs.

Police investigated and have issued a formal warning to one person who made a threat against the Radio Live host and presenter of TV3 show Story.

Garner described the threats as "revolting and vile".

One of the threats said: "I'm coming for you ... Your address is being shared so enjoy your new lifestyle f*****."

A separate threat from a second person said: "Eat s*** you need a f***ing bullet, if any pit bull attacks again I hope its [sic] you ..."

Garner's employer MediaWorks reported three separate threats, made via private messages on Facebook, to police.

Officers quickly identified the culprits, and at least one person has been issued with a formal warning by police.

Garner said on Friday he was grateful for the police response.

"I want to thank the NZ Police for acting so quickly and for sorting this issue out. Everyone is entitled to their opinion but threatening to kill someone as a result is a step too far.

"I won't back down from my views or be shaken by the nature of the threats that came my way - we need these pit bulls banned. We can do more. And we must.

"Four attacks in a week. What other evidence do we need?"

Garner wrote a column on Monday urging politicians to ban pitbulls after a seven-year-old boy was savaged by his uncle's dog in Auckland at the weekend.

"I hate them," Garner said in an opinion piece published on Radio Live's website on Monday.

"We must ban them. We don't need them. What's the good bit? I'm sick of politicians saying this is all too hard."

He received several violent threats soon after the column was published.

Garner wrote that pitbulls were "horrible".

"How many more children need to be attacked and possibly killed before someone takes decisive action. The law no longer works.

"We need to ban pitbulls, fullstop. No ifs, no buts, no maybes."

Garner also writes a column for Stuff.co.nz and The Dominion Post and The Press newspapers.

For this work he is a finalist for opinion writer of the year at the Canon Media Awards in May.