Germany has halted signing a controversial anti-piracy accord, the Anti-Counterfeiting Trade Agreement (Acta), after the justice ministry voiced concerns.

A foreign ministry spokesperson told AFP that the delay was to "give us time to carry out further discussions".

Latvia also put off signing on Friday. Poland, the Czech Republic and Slovakia have already delayed ratification.

International protests against the agreement are expected on Saturday.

Measures within Acta to tackle online piracy have proven particularly controversial.

"Hacktivists" claiming to act on behalf of Anonymous have attacked official websites supporting the international agreement.

Supporters of the treaty argue that the measures are necessary to clamp down on growing levels of piracy.

The treaty has yet to be ratified by the European Parliament.