Children as young as eight have been abused in Irish-made pornographic videos seized by gardai in recent months. On Wednesday the possession of such material became a criminal offence, with the passing into law of the Child Trafficking and Pornography Act.

The legislation will "greatly assist" the prosecution of paedophiles who exchange material among themselves, according to a Garda source involved in investigating child abuse.

Last Monday a Limerick journalist, Frank Hamilton (49), was sentenced to seven years' imprisonment for assaulting a teenage schoolgirl in a hotel bedroom in 1994 and 1995. Gardai and Customs officers found 69 child pornography and bestiality videos in a raid.

The court heard that Hamilton had been receiving the material at a Limerick address under an alias. The man whose name he had been using did not know anything about the material.

Up to now, child pornography has been seized as a by-product of investigations into child sexual abuse, or as a part of the work of Customs officials. With possession becoming a crime in itself, gardai can investigate people suspected of making, distributing and using child pornography. Under the new laws, those found guilty of trafficking children or making pornography can be jailed for 14 years.

Gardai do not have evidence that money is being made from domestic producers of child pornography. The operations appear to be in backroom set-ups, with photographic material and videos shared between paedophiles. Often this exchange takes place on the Internet, with private exchange between email addresses and more public bulletin boards where material can be downloaded, either free of charge or via a credit card payment.

According to the Garda source, those children featured in Internet pornography are frequently younger than eight. Much of the material originates in Holland, Germany and Japan, and it can be decades old. However, more new material has been generated over the past year.

"The Act will greatly assist us", the Garda source said. The authorities have co-operated with other police forces looking for information on pornographic material, but unless they were investigating a particular crime it was not possible to investigate the pornography itself.

"These people are not in it for money", the source said. "It's extremely important to highlight this, because young people get sucked into the scene so easily."

Under the Act, a District Court judge can issued a search warrant on the word of a Garda sergeant. The offence of distributing child pornography will apply not just to visual depictions of children being sexually abused, but also to any material containing children witnessing obscene acts, any audio material, and any written material advocating paedophilia.

Company directors, secretaries and managers can also be prosecuted if it is proved that corporate concerns were involved in the trade, with their consent.