The father of an Irishman described by the FBI as “the largest facilitator of child pornography on the planet” has insisted his son is completely innocent.

Antonio Marques spoke out in defence of his 28-year-old son Eric Eoin Marques who is held in custody in Dublin pending the outcome of a US extradition request.

The son has a Brazilian father and Irish mother and moved to Ireland when he was very young.

Marques senior, 60, told the Irish Independent: “All I can say is that my son is completely innocent. All he was doing was renting web space.”

Mr Marques, who worked for Irish Rail for more than 15 years and now works for Etihad Rail in the United Arab Emirates, claimed that his son had stipulated to customers that he would not tolerate illegal activity on the websites.

“He doesn’t allow it”, said his father, who acknowledged that illegal material had been discovered on sites hosted by his son’s company.

He added: “There is something bad in there, but it is nothing to do with him.”

He did not believe his son, who has both Irish and US citizenship, should be punished for the crimes of others.

He said: “If I rent out an apartment and somebody does a crime in it, am I to be prosecuted?”

US authorities are seeking to extradite Eric Eoin Marques to the state of Maryland to face charges of distributing, conspiring to distribute and advertising child pornography – as well as aiding and abetting advertising of child pornography – as part of a major international investigation.

If convicted in the US, New York-born Marques, who arrived in Ireland aged five and whose mother is Irish and father Brazilian, faces up to 30 years in prison. The irish penalty for similar offences carries a maximum 14 years.

The FBI suspect him being the founder of Freedom Hosting, one of the biggest anonymous hosts in the ‘dark’ or hidden web, where people can share files without being traced.

The US has nine days to formally request Marques’ extradition.

Following a brief appearance at the High Court in Dublin on Thursday, he was remanded in custody until Thursday of next week.

At an earlier court hearing, an FBI agent described Marques as the largest facilitator of child pornography on the planet.