A US judge has ‌ordered a psychiatric evaluation for the estranged father of Meghan, Duchess of Sussex, to determine if he is ‌mentally fit to answer to charges accusing him of being a child sex predator.

US Magistrate Judge Lindsay Griffin in Tampa wrote ‌in a two-page order on Friday (local time) that 82-year-old Thomas Markle showed a “lack of recall” in his initial court appearance.

That raised questions for the judge about whether he was competent to face prosecution.

Markle was arrested last week on a single federal count of possessing child sexual abuse material. It allegedly includes two explicit photographs of himself posed with a naked underage girl and other ‌images of him ‌with children in ⁠various stages of undress.

According to an FBI affidavit filed in court as part of the criminal complaint lodged against Markle, federal agents seized the material in question, part of a cache of slides, film negatives and books, from storage units Markle had rented in Los Angeles since 2008.

Commenting ⁠on the case, FBI director Kash Patel said Markle “targeted ‌innocent children ​and sought to steal their innocence through his criminal actions”.

Markle most recently lived in Lakeland, Florida, where he is apparently a nursing home patient.

No plea was entered during Friday’s hearing, and the judge permitted Markle to be ​released from custody on personal recognisance on condition that he submit to home detention and electronic monitoring.

The federal public defender assigned to represent him, Mary Claire Wolf, did not immediately respond to a request for comment.

In ​a ​court order after the hearing, Griffin said ​she found “reasonable cause to believe” that Markle may “suffer from a mental ‌disease or defect rendering him mentally incompetent to the extent that he is unable to understand the nature and consequences of the proceedings against him or to assist properly in his defence”.

Griffin said she based her findings on unspecified information provided about his health condition, his “advanced age, and lack of recall”.

The latest developments come after it emerged at the weekend that Meghan Markle’s mother, Doria Ragland, had reportedly helped identify her former husband in the criminal photos.

Britain’s Sun newspaper reports that Ragland, a former social worker who was married to Markle from 1979-87, was shown redacted versions of the suspected child sexual abuse images and helped identify him as the man pictured.

Griffin also appointed Dr Amie Gerodimos, a forensic psychiatrist, to conduct ​an independent psychiatric exam of Markle and to render a diagnosis of his condition with a finding on his mental ​fitness to stand trial.

Griffin set ⁠a November 20 deadline for Gerodimos to report back to the court.

Meghan and husband Prince Harry are due in Brussels on Tuesday (local time) to promote an initiative that honours children who have died due to the harms of social media.

The duchess had been scheduled to deliver a speech at the event but abruptly withdrew on Monday. Britain’s Telegraph reports she is “not strong enough” to speak publicly following her father’s arrest.

1800 RESPECT 1800 737 732

National Sexual Abuse and Redress Support Service 1800 211 028

Lifeline 131 114

beyondblue 1300 224 636

-with AAP