A US Air Force lieutenant colonel who was working at the US embassy in London shared child sex abuse images with his brother, a military hearing in the United States has heard.
Lt Col Michael Morris is accused of sending material featuring children as young as two, some of whom were wearing nappies, to his sibling.
Prosecutors said the pair also traded explicit messages about their sexual preferences for school-age boys.
The officer, who held the post of assistant military attache at the high-profile diplomatic mission in the capital, is alleged to have encrypted a number of electronic devices at his UK home.
This is said to have happened after he learned his brother had been remanded in custody in the US on a string of charges relating to child sex abuse material.
He was flown back to the States in August “under escort” before he could be questioned by British police.
The case has prompted renewed concerns at Westminster over US authorities ignoring the legal jurisdiction of the host country, despite alleged offences being committed on UK soil.
Lt Col Morris appeared at a preliminary hearing on Friday, conducted by the Air Force District of Washington at Joint Base Andrews in Maryland.
He is facing a series of charges, including possession, distribution and conspiracy to produce “child pornography”. He is also accused of obstructing justice and “conduct unbecoming an officer and a gentleman”.
The hearing was told Lt Col Morris had sent his brother videos of himself in uniform committing sex acts, including in public on a bus.
In a message accompanying the bus video, he is alleged to have said: “I know I shouldn’t, but I can’t help myself.”
He attended the review dressed in uniform, flanked by defence lawyers. He rose to confirm his name, but did not make a statement.
A decision will now be made on whether probable cause exists to believe the charged offences were committed and if the case should be referred to court-martial.
Lt Col Morris could face a sentence of up to 155 years behind bars if eventually convicted, the hearing was told.
His brother, Benjamin Morris, was arrested earlier this year by police in Illinois after an investigation sparked by a group that tracks down alleged paedophiles and is currently facing trial.
Prosecutors in the Benjamin Morris case claimed he had exchanged child sex abuse material with his brother while Lt Col Morris was based in London.
Detective Jonathan Shappard, of Rock Island Police Department in Illinois, giving evidence by videolink, said he had alerted air force authorities after discovering material on Benjamin Morris’s phone.
The hearing was told the brothers communicated by text and the Telegram messaging app.
Asked about the material shared by the brothers, Det Shappard said: “There’s videos depicting children from ages two or three engaging in sexual acts.”
He said the pair had also discussed “purging” their accounts of incriminating content.
Special agent Jared Fernandez of the Air Force office of special investigations, confirmed some of the young children featured in the images were wearing “diapers”, the US term for nappies.
He said a search had been carried out of Lt Col Morris’s UK address after being contacted by Rock Island police, and some 25 electronic devices were seized and sent for examination. Up to 10 were found to have been intentionally encrypted.
Nathan Freeburg, acting for Lt Col Collins, pointed out no child abuse material had been recovered from his client’s property.
Mr Fernandez said: “Everything is still under examination at this time.”
A decision on how the case proceeds is now pending.
In its most recent statement, the Metropolitan Police in London said: “We have been liaising regularly with the US authorities since they made us aware on Tuesday August 25 of their investigation into suspected offences relating to indecent images of children.
“We are aware that charges have been brought in the US in relation to this case and that legal proceedings are ongoing. We remain in contact with the US authorities.”
Downing Street had raised concerns after an American fighter pilot avoided a trial under English law for strangling a woman in Cambridge while off duty.
Captain Jacob Wulfson was tried at a court-martial on a US airbase and was jailed for six months after being convicted of strangulation.
He was acquitted of charges of sexual assault and aggravated sexual contact.
The case has also been likened to that of US state department employee Anne Sacoolas who caused the death of teenager Harry Dunn in a car crash in Northamptonshire in 2019.
Sacoolas was able to leave the country shortly after causing the fatal collision after the US asserted diplomatic immunity on her behalf.
She eventually pleaded guilty to causing death by careless driving at a virtual High Court hearing in December 2022 and was sentenced to eight months in prison, suspended for a year.
