A leading youth campaigner against rape and sexual violence has been arrested for possession of child pornography and attempting to arrange sexual encounters with children.

Joel Davis, 22, co-founder of advocacy group Youth to End Sexual Violence and a former UN youth ambassador for Sexual Violence in Conflict, appeared in court in Manhattan on Tuesday.

He has been charged with enticement of a minor to engage in sexual activity and attempted sexual exploitation of a minor, as well as child pornography offences.

In text exchanges with FBI agents posing as paedophiles, Davis “allegedly arranged to meet the nine-year-old daughter of one of the undercover agents and with the purported two-year-old daughter of the officer's girlfriend”, the Daily Mail reports.

Child pornography, including images of infants and toddlers being abused, was allegedly also found in his possession.

Police said that, during questioning after his arrest, Davis “admitted to sexually abusing a 13-year-old boy in the past and keeping child porn images on his phone”, NBC reports.

Davis is currently listed on his LinkedIn profile as director of the International Campaign to Stop Rape and Gender Violence in Conflict, a project founded in 2012 by Nobel laureates which now involves more than 5,000 people and organisations.

“In the same period he exchanged messages with the undercover agents, Davis also addressed an independently-organised TED conference, explaining that his first job was to transcribe the testimony of rape victims in Congo,” news agency BNO News reports.

In a statement, FBI assistant director William F. Sweeney Jr. said that Davis’ alleged crimes indicate “the highest degree of hypocrisy” in light of his public profile as a defender of sexually-exploited youth.

“As if this wasn't repulsive enough, Davis allegedly possessed and distributed utterly explicit images of innocent infants and toddlers being sexually abused by adults,” Sweeney said.

US Attorney Geoffrey Berman said that the conduct alleged against Davis is “as unfathomable as it is sickening”.

Davis has yet to enter a plea to the charges.