There is a range of powers that enable the forfeiture of such items.
Section 143 of the Powers of Criminal Courts (Sentencing) Act 2000 provides a general power of forfeiture allowing the courts, on conviction of an offence, to make an order depriving an offender of any rights in lawfully seized articles or articles in the possession or under the control of the offender at arrest or summons which were used, or intended to be used, for the purpose of committing, or facilitating the commission of, an offence or in relation to which the offender was convicted of an offence involving unlawful possession of property.
Section 5 of, and the Schedule to, the Protection of Children Act 1978 allows the forfeiture of any indecent photograph, pseudo-photograph or prohibited image of a child and any property which it is not reasonably practicable to separate from that property following any lawful seizure. The police must give notice of any intended forfeiture of such property and where forfeiture is contested the court must determine the issue.
Section 3 of the Obscene Publications Act 1959 allows the courts power to order the forfeiture of obscene articles kept for publication which have been seized under a warrant issued under that section.