A 28 year-old Senate aide was arrested on Friday in Washington for attempting to sexually exploit a minor.

Mike McHaney had previously been employed for the US largest LGBT rights group, Human Rights Campaign, based in Washington DC.

The scheduler for Democratic Senator Maria Cantwell of Washington state was arrested on charges that he had arranged to have sex with what he thought was a 13-year-old boy.

He had agreed to arrange a three-way sexual encounter with the teenager and a cooperating witness, who was secretly working with FBI investigators.

According to a federal court document obtained by the SmokingGun.com, the undercover informant, who knew Mr McHaney, told federal authorities that the Senate aide “had a sexual interest in male children” and that they had they “exchanged images of child pornography with each other on previous occasions.”

The two were chatting on line on Friday afternoon, when the undercover informant asked McHaney whether he was interested in engaging in anal sex with a 13 year-old boy.

McHaney allegedly replied he was. He then asked for a photo of the boy and arranged a location where he later showed up, and where he was arrested.

Human Rights Campaign confirmed that McHaney’s had worked as an executive scheduler for them from September 2005 to May 2006, but added that his leaving the group had had nothing to do with the reason why he had been arrested.

HRC spokesperson Brad Luna declined to answer questions about the nature of McHaney’s departure, citing confidentiality of personnel records.

Before working in for the gay rights group, Mr McHaney had also worked on the presidential campaign of Senator John Kerry in 2004.

McHaney was fired from Senator Cantwell’s office after the arrest.

Her chief of staff, Michael Meehan, said that they were informed about the arrest by the FBI.

“Our office has and will continue to fully co-operate with the ongoing federal criminal investigation. Senator Cantwell has zero tolerance for crimes against children” he said.