WARNING: THIS ARTICLE CONTAINS DETAILS OF GRAPHIC CONTENT.

Authorities have revealed graphic and disturbing details about the child abuse material that they say was uncovered at two storage units belonging to Thomas Markle Sr. before his arrest, including “sexually explicit photographs of himself with prepubescent girls.”

The FBI seized a total of 78 items containing suspected child pornography from the units, both of which are “registered to Markle within the Central District of California,” according to the criminal complaint filed by special agent Laura Carter on Friday.

The former lighting director had been renting the Los Angeles-area storage units for nearly 20 years, most recently making auto payments last month, according to the unsealed documents.

Among the disturbing images found inside were photos of a man performing sexually abusive acts on a female who appeared to be prepubescent, per the court document obtained by Page Six.

FBI officials have identified the man as Markle, as corroborated by individuals who have known him since the 1970s.

One of the graphic photos is believed to have been taken at the Anahaw Lodge in the Philippines, based on background clues, according to the complaint.

Additionally, the unit is understood to have contained additional pictures of Markle with “children in various stages of undress.”

Page Six has reached out to the FBI.

Meghan Markle’s dad was taken into custody on Friday, with The Post confirming federal agents arrested him at the Maravida Senior Living care home in Lakeland, Florida.

Thomas Sr. has been living there amid reported dementia struggles.

He will make his first court appearance Friday at 1:30 p.m. in United States District Court in the Middle District of Florida, in Tampa.

In a statement issued by the Department of Justice, First Assistant United States Attorney Bill Essayli denounced the heinous materials uncovered in the storage units and vowed to “prosecute Mr. Markle to the fullest extent of the law.”

“Mr. Markle allegedly targeted innocent children and sought to steal their innocence through his criminal actions,” Essayli added. “Working with our Justice Department partners, our agents moved quickly, identified and located the explicit material, and arrested Mr. Markle in Florida.

“{This FBI will use every single resource at our disposal to protect innocent kids – any predator who targets children will have zero safe haven in this country or anywhere they try to hide.”

FBI Director Kash Patel echoed those comments in his own statement shared Friday.

Thomas Sr. resided in the Philippines until May, when he moved back to the United States for “ongoing medical care,” per daughter Samantha Markle.

Five months later, his son, Thomas Markle Jr., announced he had discovered alleged child abuse materials in his dad’s Philippines home and turned his findings over to the authorities.

The 60-year-old claimed in October to have found “hundreds, if not thousands” of images — some allegedly depicting girls between the ages of 10 and 11 engaging in “sex acts” — in storage boxes.

Thomas denounced his son’s accusations as “sick lies.”

Samantha, meanwhile, accused her brother of seeking “revenge” on Thomas Sr., while Meghan released a statement about how “deeply distressed” she felt about the allegations.

She and Prince Harry did not release a subsequent comment when the Daily Mail investigated Thomas Sr.’s storage unit in Mexico, reporting on its “vile” contents last week.

The Duke and Duchess of Sussex have, similarly, remained silent regarding his arrest, as have Meghan’s half-siblings.

Thomas Jr., notably, was named as a person of interest in the child porn probe during a press conference Thursday.

“We have a witness [who says] underage girls were being brought to his house. We will investigate whether the son was involved in the crime,” Philippine Interior Secretary Jonvic Remulla said. “To accuse the father only is only half the police work. There are signs that point that the son is involved.”

The window installer is not currently considered a suspect.

If you or someone you know is affected by any of the issues raised in this story, call the Sexual Assault Hotline at 1-800-330-0226.