John Paulson may be losing his Midas touch when it comes to this Canadian gold miner.

The billionaire hedgie behind Paulson & Co — who famously pocketed $4 billion after betting against subprime mortgages ahead of the housing crisis — fired off yet another testy letter on Tuesday to shareholders of Detour Gold, complaining that the board has ignored his pleas to put the company up for sale.

Paulson & Co, which manages $9 billion — down from a 2011 peak of $38 billion — has a 5.4 percent stake in Detour Gold and wants to replace the board with its eight nominees.

The hedge fund’s nine-year relationship with Detour Gold had been “very constructive,” Paulson’s partner Marcelo Kim told The Post, noting that Detour Gold had its “arms wide open” when the hedge fund initially invested.

But the relationship recently soured as Detour Gold shares are down 30 percent this year.

“The board must be held accountable for the value destruction, disregard for shareholders, poor disclosure practices, failing leadership and culture of entitlement at Detour Gold over many years,” Paulson and Kim wrote in Tuesday’s letter.

The hedge fund laments that its nine years as a loyal shareholder haven’t won it any respect from Detour Gold.

“Despite our longstanding support for the company, through equity and debt investments, our attempts to engage constructively were rebuffed on multiple occasions,” Paulson and Kim wrote.

Amid underperformance, Paulson & Co began pushing the company in July to revamp its board with Paulson’s nominees and consider a sale.

The hedgies noted that Detour Gold’s recent decision to add three new board members was “concerning” given that companies under activist attack often make “modifications around the edges.”

Nevertheless, Paulson said Tuesday he was willing to meet the new directors to see if they were a good fit for his hedge fund’s slate.

Detour Gold reps declined to comment.