POLICE will be able to destroy computers carrying suspected child pornography even where the material is highly encrypted and impossible to access, under a tightening of federal sex offence laws.

But police are also understood to be pressing the government for greater powers against suspects who refuse to reveal passwords.

At present, offenders who refuse to reveal passwords can be jailed for up to six months but are able to avoid potentially longer sentences for incriminating material.

Australian Federal Police Commissioner Tony Negus said yesterday the new laws would give the police the ability to destroy computers - not just files - to ensure that potentially criminal material is not returned to offenders.

''When we seize computer hard drives we are talking about enormous volumes of data that is stored,'' he said.