Tesla investors have issued an open letter to Elon Musk, demanding that he apologize for his “pedo” comment about Vernon Unsworth — the British cave diver who criticized his rescue efforts in Thailand.

Musk, who serves as Tesla’s CEO, came under fire over the weekend after he called out Unsworth on Twitter for comments he made during an interview with CNN.

The diving expert blasted the Silicon Valley billionaire for trying to help with the rescue in Thailand, calling his involvement and mini-submarine idea “a PR stunt.”

Musk shot back on Sunday, saying: “Never saw this British expat guy who lives in Thailand (sus) at any point when we were in the caves…Sorry pedo guy.”

Tesla investors posted their open letter online Tuesday, calling for an apology.

“The exchange with Vern Unsworth crossed the line,” wrote Loup Ventures, a venture capital firm based in Minneapolis and New York. “I suspect you would agree given you deleted the string from Twitter, but it will take more than that to regain investor confidence.”

For many, Musk’s tweet was the last straw following his heated Twitter exchanges in recent months and repeated attacks on reporters, regulators and now rescuers.

“Over the last 6 months, there have been too many examples of concerning behavior that is shaking investor confidence,” the letter added. “In our view, your outburst at analysts on the March 2018 earnings call, your ongoing frustration with short sellers and the media, your June email exchange with the saboteur, and your confrontation on Twitter with cave diver Vern Unsworth each raised flags with investors.”

The investors went on to say that Musk’s behavior was “fueling an unhelpful perception” of his leadership — calling it “thin-skinned and short-tempered.”

“It could have a dramatic negative impact on the company,” Gene Munster, head of research at Loup Ventures, told The Guardian.

“The irony here is that their brand is word of mouth,” he said, in reference to Tesla.

“[These scandals] could negatively impact demand and access to capital.”

Munster and other investors said that while they’ve sometimes agreed with Musk’s Twitter statements in the past, they couldn’t back him up this time.

“This is different,” explained James Anderson, partner at Baillie Gifford, Tesla’s fourth-largest shareholder. “We are in contact with the company and we are hopeful that it is being taken with due seriousness.”

Anderson and others noted how Tesla has been at the forefront of electric car development and reducing carbon emissions — and Musk’s controversial Twitter comments could jeopardize that.

“[Investors are] frustrated that the real steps towards this are being overshadowed and undermined by this saga,” Anderson said.

“It has to start with an apology,” Munster added.

Loup Ventures investors agreed.

“Thankfully, the road to regaining investor confidence is well traveled,” their letter said. “You might consider taking a Twitter sabbatical. Twitter might keep Tesla in the news, but won’t help continued improvements in production and product.”