The Power of the Dog has been adapted by Campion from a 1967 novel, set in the 1920s, about two wealthy brothers who fall out. Their lives are permanently altered when one falls in love with a widow and brings the woman and her son to live on their isolated ranch.
It traces the tense relationship between two brothers. Cumberbatch's character is a bullying repressed homosexual, who terrorises his new sister-in-law, (Dunst).
On Thursday the Otago Daily Times captured images of Dunst doing laps of Ōamaru's Harbour St and Tyne St beside Smit-McPhee, in a vintage car in period costume, with Campion directing.
Campion has cast the actress' fiance and Fargo co-star Jesse Plemons as Cumberbatch's brother in her movie.
Cumberbatch is understood to have been staying in a stately home in Alexandra with his family. When the Sherlock star was in New Zealand filming The Hobbit in 2012, he was pictured enjoying his time in Queenstown, with numerous shots of him skydiving. No such pix have appeared this time around.
On star Sam Neill's winery website page Two Paddocks, there is a picture from 2012 of the Dr Strange actor enjoying a bottle of the Jurassic Park actor's finest plonk.
Neill remained tight-lipped about whether he caught up with Cumberbatch during his current visit.
"We are very discreet when it comes to our friends/clients/ fans/bon vivants/bludgers/connoisseurs. So, our lips are sealed," he told Spy
The ODT also reported Dunst and Plemons had dined at Cucina restaurant in Ōamaru on Tuesday night.
Cucina co-owner Yanina Tacchini said it was "awesome" to have the couple enjoy their fare.
Tacchini said the pair were very laidback and came up to the bar just like normal people.
The restaurant owner also revealed that Dunst's mother looked after the couple's young son while they enjoyed a night out, and that they were due to fly from Dunedin to Auckland this week.
All eyes are now out for some major star spotting around town.
