The CMA’s disclosure document revealed that Lesley Ainsworth has 565 shares in Royal Dutch Shell and 51,250 units in Foresight Venture Capital Trust, which focuses on investing in solar energy projects.
The CMA said it does not believe that the interests of those sitting on the panel will prejudice the impartial investigation.
The CMA also revealed that fellow panel member Roger Witcomb was a non-executive board member of small energy supplier Utilita between 2005 and 2009.
Two members of CMA staff are also named as having previously working in the energy sector.
Nenan Njegovan, a director of economic on the CMA staff team, was employed by Ofgem until July 2012, where he worked on, among other things, licence enforcement proceeding against the major supply companies.
Duncan Mills, another economist on the CMA staff team, was employed as a regulatory manager with British Gas between January 2011 and January 2012.
In the document the CMA stated that the inquiry panel and the CMA staff will be able to “discharge its functions in an independent and impartial manner”.
The CMA also said: “All of the inquiry group members are consumers of gas and electricity in their private capacity.”