A former aide to Prime Minister David Cameron has been convicted of downloading pictures of scantily-clad girls as young as 10 in sexual poses.
Patrick Rock, who turned 65 on Wednesday, faced 20 charges of making an indecent photograph of a child.
Rock, of Fulham, south-west London, had claimed the 20 images he downloaded onto his iPad over three days in August 2013 were not indecent. The jury in his trial at Southwark Crown Court in London took more than eight hours to convict him of five counts.
He was acquitted of three similar charges, while jurors were unable to agree on 12 other counts and were discharged, meaning the charges will lie of file.
The court heard that the youngest of the girls in the pictures was aged just 10 years and four months when he downloaded it - meaning she would have been younger when it was taken. While none of the girls were naked, prosecutors claimed they were in "sexualised" poses in skimpy clothing, including swimwear and bras.
The court heard Rock downloaded the images at a golf club while on a trip to visit family in the US.
Prosecutor Tom Forster said: "If anything, Mr Rock's trip to the US, although for other purposes, to commit these offences is of interest, say the Crown.
"He used the internet specifically at the golf club away from the family home. There was no WiFi at the address."
Sasha Wass QC, in mitigation, said her client had been in America after his mother had died in order to handle her affairs.
Rock's sister, in a statement read to the court, said at the time of the offences he had been "sad, angry and holding on to the fact he had not been with mum when she died".
Upon finding out the US authorities were interested in searching his iPad, Rock handed himself in, Wass said.
"Mr Rock self-reported to those he worked for, mainly the Prime Minister's private secretary, before he was even arrested for this matter," she said.
"Mr Rock was told by his sister in America police were interested in the contents of his iPad.
"Mr Rock immediately spoke to the Prime Minister's private secretary, who in turn reported him to the National Crime Agency in this country and Mr Rock immediately resigned.
"In our submission he did the honourable thing from the outset.
"Mr Rock always accepted he had behaved in a way that was morally wrong by downloading those images."
Rock had sought treatment at a charity called the Lucy Faithfull Foundation, she added.
Police in the US did not prosecute Rock because they had found there was no "child pornography", Wass added.
Meanwhile "no images were found at all" in searches of his laptop, phone and iPad by UK police.
Adjourning until Thursday for sentencing, Judge Alistair McCreath said: "This is a man who is convicted of the downloading of, in relative terms, a small number of images who has an unblemished history."