A federal court judge has extended an injunction that blocked a competitor to Irvine-based Allergan Inc.’s flagship Botox after allegations that trade secrets were stolen.

U.S. District Judge Andrew Guilford in Santa Ana has entered an order against Merz Aesthetics, a U.S. unit of Germany’s Merz Pharma GmbH. The move means that a previous order prohibiting Merz from selling or soliciting purchase of its Xeomin drug for cosmetic use in the U.S. will remain in place until January 9, 2013.