A female business acquaintance of accused Gilgo Beach serial killer Rex Heuermann revealed a creepy voice message Sunday that he once left her.

Interior Designer Dominique Vidal said she met the suspected murderer in a networking group for architects and designers — which led to a chilling chat in a Big Apple bar and several “odd” telephone calls.

“Hey, this is Rex from the … group,” a man can be heard saying in a February voicemail recording Vidal shared on TikTok on Sunday.

“I actually heard you are no longer part of the group. I still wanted to talk to you,” Heuermann said, according to Vidal.

“I had a question for you. Did also want to touch base. So if you get an opportunity, you can always find me at the office or feel free to use my cell,” he said. “Hope you’re doing good. Hope to talk to you soon.Thanks.”

Vidal, who lives in Westchester County, said she left the networking group in part because her job got busy — but also because of Heuermann, who she described as arrogant, sweaty and just creepy.

“He left this [voicemail] for me end of February after I left the group,” she said on TikTok on Sunday. “Previous to that, he did call me a couple of times. I answered the phone. Nothing really significant. I found it odd he was calling me because I had no work for him. There’s no ongoing relationship. We were just two people who used to be in the same networking group.

“There’s nothing incredibly scary about the voicemail, besides the fact that he is the Gilgo Beach murderer,” Vidal said, referring to the charges against Heuermann, which he has denied.

Heuermann, 59, a married father of two from Massapequa Park, was arrested Thursday and charged with murder in the deaths of three women whose remains were found near his home in 2010.

The women — Melissa Barthelemy, 24; Megan Waterman, 22, and Lynn Costello, 27 — were among 11 bodies found strewn along a marshy stretch on the South Shore.

Police said Heuermann is also the prime suspect in the death of Maureen Brainard-Barnes, 25.

The crimes remained unsolved for 13 years until the arrest last week.

In a TikTok post Saturday, Vidal recalled a bizarre chat she had with Heuermann at a Manhattan bar after a network group meeting, during which he asked if she knew about the then-unsolved murders.

“I’m like, ‘Yeah, of course I know,’ ” she said she told him at the time. “And he goes on to tell me, ‘Yeah, that’s a serial killer that was never caught in m hometown, my neighborhood where I live.’ “

Vidal said she then joked, “Anybody could be a serial killer,” which Heuermann laughed at.