That made it the third most watched programme on New Zealand television for the day behind One News and Sunday, and the most-watched show in the 7.30pm to 11pm time slot.
In the previous weeks, it sat as the fourth most viewed show overall on Sundays.
Throng.co.nz editor Regan Cunliffe said although the numbers were above other shows with a strong following, such as weeknight cooking show My Kitchen Rules which pulled in up to 300,000 viewers, they were behind all-time hits such as New Zealand's Got Talent which sometimes drew close to one million.
"It hasn't stood out as far as numbers are concerned for me. But in saying that, a lot of people are hooked on the series," he said. "It will be interesting to see if TVNZ decide to screen the second season straight after it has run in the UK or wait until next winter again."
Mr Cunliffe said it was likely many fans had watched the show "elsewhere" - a reference to the ready availability of movies and television episodes online.
"It's almost 12 months old now so there is that delay factor where the show had already screened quite a significant time ago.
"So those people who might have been interested may have already seen it elsewhere.
"Now people are hooked on it and know it's a good show, I suspect there might be a few people who source it elsewhere."
TVNZ's programming general manager, John Kelly said the series was popular.
"Viewers are loving watching Broadchurch and we're thrilled that this superb drama is a must-see and talked-about event each Sunday night.
"Season two is currently in production and we can't wait to bring it to New Zealand."
He did not answer questions about the delayed screening to New Zealand audiences, nor when the next season was likely to be shown here.
