Joe Cresswell and Daniel Hemming from RPC cover high court rules on agency relationships and the definition of "control" for purposes of disclosure in this piece.  

In short, the High Court recently held that a third party that was authorised to conduct contractual negotiations on behalf of a defendant - but not to sign contracts - was acting as an agent, and that relevant documents that it had created were therefore in the defendant's control and should be disclosed.

This piece really highlights the importance of understanding the definition of ‘control’ for in disclosure. It shows when it comes to control/ agency, the court will primarily focus on the substance and not the form of relationships between parties. As the authors explain, it also “confirms that agency may be established even where an agent does not have the power to bind its principal to a contract.”

Parties involved in proceedings, where there might be agent-principal relationships, should think about this when considering their disclosure obligations.

For more on control take a look at some of my previous posts.