Artikel 39

1. Officials of one Member, keeping under surveillance in the territory of this Member a person about whom there are serious grounds to believe that he or she is involved in a customs offence, may continue the surveillance in the territory of another Member subject to a prior request, authorization and any conditions the requested Member may impose.
2. If, for particularly urgent reasons, prior authorization cannot be requested, surveillance pursuant to paragraph 1 of this Article may be continued provided that the competent authorities of the Member in whose territory the surveillance is to be continued, are immediately informed of the crossing of the border and a formal request for authorization, outlining the grounds for crossing the border without prior authorization, is submitted as soon as possible.