Prosser is survived by his two daughters Olivia, 12, Gabrielle, 10 and former partner Mel Francis.
He had been married to Elaine for the past three years.
New Zealand First MP Richard Prosser with his daughters Gabrielle, 1, Olivia, 3 and partner Mel Francis at their home in north Canterbury in February 2013. Photo / File
Shortly after he entered Parliament in November 2011, and soon afterwards it emerged he had previously advocated banning the burqa in New Zealand in an article for Investigate magazine.
He released a book outlining his political views called Uncommon Dissent in 2012, in which he claimed that New Zealand and Western society had been "hijacked by a conspiracy of Silly Little Girls".
Prosser's most controversial moment as an MP was his "Wogistan" comment the following year.
Prosser stated in his Investigate column, Eyes Right: "If you are a young male, aged between say about 19 and about 35, and you're a Muslim, or you look like a Muslim, or you come from a Muslim country, then you are not welcome to travel on any of the West's airlines."
Richard Prosser, second from left, with NZ First leader Winston Peters and caucus colleagues during his time in Parliament. Photo / File
Prosser further stated the rights of New Zealanders were being "denigrated by a sorry pack of misogynist troglodytes from Wogistan, threatening our way of life and security of travel in the name of their stone age religion, its barbaric attitudes towards women, democracy, and individual choice".
The spur for the column was the confiscation of his pocket knife at Christchurch Airport.
Peters said he was disappointed in Prosser's comments at the time, and Prosser apologised and had dinner with a Muslim couple who wrote to the Herald to challenge his comments - offering a bouquet of flowers and a box of chocolates as a peace offering.
Prosser also arranged a mosque visit in Ranui, the West Auckland suburb where he was born.
In the wake of his death, former NZ First deputy leader Tracey Martin said she hoped people would think of his two young daughters.
"He has two little girls. No matter what Richard did or was, I hope people think of them," Martin said.
Richard Prosser has died suddenly in Britain. Photo / Supplied
Prosser was a qualified winemaker and viticulturist, and had previously worked as a pub manager, a truck driver and also in the agricultural irrigation industry.
It was Labour's scrapping of the Air Force combat wing that made him enter politics, Prosser said.
In 2005, he stood for Democrats for Social Credit which advocated for compulsory military training, but joined NZ First after hearing Peters speak at the Rangiora RSA.
He was involved with a pressure group "South Island First" that wanted to establish a southern parliament.
As NZ First's outdoor recreation spokesman, Prosser spoke against the use of 1080, and rubbished National's plan of making NZ pest-free by 2050.
"Our birds and lizards have co-existed alongside ferrets and stoats for more than 130 years, cats for 200 years, and rats for more than 800 years, yet still we have birds and lizards," he said at the time.
In May 2020 Prosser claimed the Covid-19 pandemic was a global conspiracy intended to transfer greater power to financial and political elites.
Radio Central reported on Facebook it was saddened to learn of the sudden death of "friend and UK correspondent Richard Prosser".
"Richard was a lovely, clever man and I will miss him greatly," it said.
"Please, please, please, open up to someone, anyone, if you have feelings of despair. There's always someone who can help and there's always someone who loves and needs you."
The Counterspin website, one of New Zealand's biggest online platforms for anti-vaccination campaigners and conspiracy theories, said: "After hearing the sad news in our chat, we can confirm that Richard Prosser has left us after a long battle with depression."
WHERE TO GET HELP:
If you are worried about your or someone else's mental health, the best place to get help is your GP or local mental health provider. However, if you or someone else is in danger or endangering others, call police immediately on 111.
