Meghan Markle’s half-brother, Thomas Markle Jr., is firing back at their father after Thomas Markle Sr. vehemently denied allegations that he possessed child pornography.

Thomas Jr., 60, called Thomas Sr.’s denial “incredible” while challenging the 82-year-old to explain how the disturbing material allegedly ended up in his possession.

“I’m sure the huge piles of evidence I’ve taken to the police today will reveal the truth once the police experts examine it,” he told the Sun in an interview published Friday.

“I would never have handed it all to the police if I wasn’t 1,000 per cent confident that it has nothing to do with me.”

Thomas Jr. continued, “I’m sure that my father does not have the same confidence — but if he does, then I challenge him to clear up the mystery of how it all got there.”

He questioned who could have placed the alleged material among his father’s belongings if Thomas Sr. was not responsible.

As Page Six previously reported, Thomas Jr. claimed he discovered “hundreds, if not thousands” of child sexual abuse images in four boxes at his father’s home in Cebu, Philippines.

He subsequently reported the alleged discovery to local police and the FBI.

Thomas Sr., however, vehemently denied the allegations Friday, calling his son’s claims “sick lies.”

“I’m shocked, I’m hurt and I’m very upset that my son is making these accusations against me,” he told the Daily Mail.

“I could never do what I’m being accused of. It’s the worst thing anyone could accuse me of.”

Thomas Sr. added, “This is bulls–t. It’s just a bunch of lies. It’s sick. I have no idea why Tom is trying to destroy me with these lies.”

Despite his father’s denial, Thomas Jr. said he hopes the allegations ultimately lead to a court appearance.

“I’m hoping that my father ends up in court either here, or most likely, back home in the US to face justice,” he told the Sun.

“That would be the best place if he wants to issue a denial and clear his name.”

Thomas Jr. also called for forensic experts to determine who downloaded and viewed the alleged material, insisting he would cooperate with investigators.

Meanwhile, Meghan, 45, said she was “deeply disturbed” by the investigation into her estranged father.

The Duchess of Sussex also revealed that she had been made aware of similar allegations years earlier, which influenced her decision to keep Thomas Sr. away from her children, Prince Archie, 7, and Princess Lilibet, 5.

“I hope it can now be understood that, despite certain media publications’ distortion over the years, any distance from my father and my choice to not allow him to have contact with our children, was for one reason: to protect them,” she said in a statement.

Meghan’s half-sister, Samantha Markle, has defended their father, accusing Thomas Jr. of fabricating the allegations for financial gain.