Accused Gilgo Beach serial killer Rex Heuermann is due in court early Tuesday over the notorious slayings of women whose bodies were found on Long Island in 2010.

Heuermann, 59, is scheduled to appear in Suffolk County Court for an 8 a.m. hearing with Judge Timothy Mazzei, according to court filings.

The dad of two faces three counts of murder over Amber Lynn Costello, 27, Melissa Barthelemy, 24, and Megan Waterman, 22, whose bodies were found on Gilgo Beach in 2010.

He is also the prime suspect in the killing of Maureen Brainard-Barnes, 25, the fourth of the so-called “Gilgo Four.”

The architect pleaded not guilty at an arraignment on July 14, the day after he was busted outside his Midtown Manhattan office.

Tuesday’s hearing comes as the now-estranged wife of Heuermann told The Post on Monday her ex’s arrest has taken a toll on their two adult children, who now “cry themselves to sleep” after learning of the shocking accusations.

Asa Ellerup, 59, said she’s been plagued with anxiety after investigators spent 12 days tearing apart her Massapequa Park home looking for evidence in the alleged murders.

“I woke up in the middle of the night, shivering,” a still-shocked Ellerup said. “Anxiety.”

“My children cry themselves to sleep. I mean, they’re not children. They’re grown adults but they’re my children, and my son has developmental disabilities and he cried himself to sleep,” she continued.

Ellerup, her special-needs son, Christopher Sheridan, 33, and her 26-year-old daughter, Victoria Heuermann, were suddenly forced out of their home following Heuermann’s July 13 arrest.

Suffolk County and state police spent nearly two weeks combing through the family’s home, even digging up the backyard in a search for body parts or “trophies” from the slayings.

Suspected serial killer Rex Heuermann — a New York City architect and married dad of two — was arrested in connection with the long-unsolved Gilgo Beach murders. The arrest is tied to the so-called “Gilgo Four,” women found wrapped in burlap within days of each other in late 2010.

The years-long investigation that led to the arrest revolved around the discovery of more than 10 sets of human remains along Ocean Parkway near Gilgo Beach in Suffolk County between December 2010 and April 2011.

Suspected serial killer Rex Heuermann — a New York City architect and married dad of two — was arrested in connection with the long-unsolved Gilgo Beach murders. The arrest is tied to the so-called “Gilgo Four,” women found wrapped in burlap within days of each other in late 2010.

Most victims were petite female sex workers with green or hazel eyes. But there were also two exceptions: a 2-year-old girl and a young Asian man.

Last week, cops packed up and left, with Ellerup and her children returning home for the first time.

The accused killer has yet to receive a single visit in jail from his family, authorities said.