1. Where there is a reasonable suspicion that a widespread infringement or widespread infringement with a Union dimension is taking place, competent authorities concerned by that infringement and the Commission shall inform each other and the single liaison offices concerned by that infringement without delay, by issuing alerts pursuant to Article 26.
2. The competent authorities concerned by the widespread infringement or widespread infringement with a Union dimension shall coordinate the investigation and enforcement measures that they take to address those infringements. They shall exchange all necessary evidence and information and provide each other and the Commission with any necessary assistance without delay.
3. The competent authorities concerned by the widespread infringement or widespread infringement with a Union dimension shall ensure that all necessary evidence and information are gathered, and that all necessary enforcement measures are taken to bring about the cessation or prohibition of that infringement.
4. Without prejudice to paragraph 2, this Regulation shall not affect national investigation and enforcement activities carried out by competent authorities in respect of the same infringement by the same trader.
5. Where appropriate, the competent authorities may invite Commission officials and other accompanying persons, who have been authorised by the Commission, to participate in the coordinated investigations, enforcement actions and other measures covered by this Chapter.