The painting by famed local artist Charles Frederick Goldie, shows a portrait of Wharekauri Tahuna, a priest who is believed to be one of the last tattooed men of his generation.

The NZ$3.75m ($2.2m; £1.7m) sale also marks the highest price ever paid for a painting at auction in New Zealand, according to the auction house.

It comes at a point of increased racial tensions in New Zealand, with the government having recently put forth a bill that Māori said would hurt their rights.

Thoughts of a Tohunga was painted nine years before Goldie died in 1947, with art critics believing it was his best work.It depicts the priest with a moko, or facial tattoo, and wearing a pendant known as a hei-tiki around his neck.

The sale, to an undisclosed buyer, makes it the most valuable Māori portrait in New Zealand art history.

“Goldie was well loved by Māori during his lifetime, [he] lived in Auckland and met his subjects,” Richard Thomson, director at the International Art Centre said, adding that this was the first time the painting had gone on sale in 33 years.

“New Zealanders have an affinity with their history and portraits by Goldie have always been sought after,” he said, adding that since 2016 his auction house has sold 13 Goldie paintings, with buyers paying more than a million New Zealand dollars each time.

Wharekauri Tahuna was one of Goldie’s favourite subjects and featured in a number of his works.

Māoris make up about 18% of New Zealand’s population, though many remain disadvantaged compared to the general population when assessed through markers such as health outcomes, household income, education levels and incarceration and mortality rates. There remains a seven-year gap in life expectancy.

Last week, political party Act – a minor partner in the coalition government – sought to pass a bill that would reintepret the country’s founding treaty with Māori people, known as the Treaty of Waitangi.

Thousands of people joined a nine-day march against the bill earlier last week.The bill passed a first reading but is unlikely to pass a second reading, as Act’s coalition partners have indicated they will not support it.