(5)Member States may accept that inspections by their competent authorities are carried out jointly with the competent authorities of the United States where this is necessary to ensure effective supervision. Member States may allow that cooperation with the competent authorities of the United States takes place under the form of joint inspections or through observers without inspection or investigation powers and without access to the confidential audit working papers, to other documents held by statutory auditors or audit firms, or to inspection or investigation reports. It is necessary that such cooperation always takes place under the conditions set out in Article 47(2) of Directive 2006/43/EC, in particular as regards the need to respect sovereignty, confidentiality and reciprocity. Any joint inspections carried out in the Union by their competent authorities and the competent authorities of the United States under Article 47 of Directive 2006/43/EC will be under the leadership of the competent authority of the Member State concerned.