A Canberra Australian Federal Police (AFP) officer and his twin brother are behind bars after police allegedly found a large quantity of child pornography, hidden cameras and a device transmitting offensive material at their home.

Key points: Police charged twin brothers with child exploitation offences yesterday

Police charged twin brothers with child exploitation offences yesterday AFP officer Joshua Tiffen allegedly showed a woman images of children

AFP officer Joshua Tiffen allegedly showed a woman images of children Both brothers were denied bail, while Kenan Tiffen indicated he would plead not guilty

Joshua Rod Tiffen and his brother Kenan Lee Tiffen, both 41, were arrested yesterday after tip-offs from two women who claimed to have been shown the material by the men at separate times.

Police said they had seized more than 400 videos.

Many of the videos allegedly featured girls between 12 and 14, but some contained younger children.

Court documents said one of the women who alerted police had made several adult films with a man named Matt, who was actually Joshua Tiffen, according to police.

Police say the woman told them "Matt" had shown her images of children on his computer, and said he would talk to female children and get them to do what he wanted.

Police also say the woman claimed she was shown an image of a three- or four-year-old girl revealing her genitals.

According to the documents, a different woman made allegations about Kenan Tiffen after going on several dates with him.

That woman said Kenan Tiffen told her he had a secret but that she must not judge him, before he showed her about 50 child abuse images.

On Friday, police told the court when they searched the men's home they found storage devices and hard drives containing hundreds of child exploitation videos.

The court heard police also found a camera that was in the process of transmitting offensive material, although they could not say whether it was receiving or sending footage.

Court documents also allege police found hidden cameras in three bedrooms the men had rented to female tenants.

'Base and vile conduct'

Joshua Tiffen, who is a serving police officer, was arrested at the Majura Police Complex before the search.

He did not indicate a plea or apply for bail in the ACT Magistrates Court on Friday.

His brother Kenan did ask for bail and indicated he would be pleading not guilty.

The court heard Kenan Tiffen was a fly-in, fly-out worker.

Police opposed bail, saying they could not be sure he would refrain from interfering with evidence, particularly material that might be stored on the cloud.

The court heard police were still trying to get access to Kenan Tiffen's phone.

Magistrate Beth Campbell rejected claims by his lawyers that the allegations against him were tenuous.

"This is base and vile conduct," she said.

"His moral compass is so different from ordinary members of the community.

"I am not confident he could control his base impulses."

Joshua Tiffen will be back in court later this month and Kenan Tiffen will return to court in July.