The Conservative Party Co-chairman Baroness Warsi is facing two separate investigations into potential breaches of ministerial conduct.
The first is by the House of Lords Standards Commissioner, who will look at allegations that she claimed £165.50 per night in accommodation expenses while living rent-free at the home of her friend, Tory official Naweed Khan.
She claims she made an "appropriate payment" to Mr Khan for the trouble of putting her up.
She is also facing a separate investigation by Sir Alex Allan, the Prime Minister's independent adviser on ministerial interests, into her failure to declare her business relationship with her friend Abid Hussain, who accompanied her on an official trip to Pakistan in July 2010.
Baroness Warsi has admitted in a letter to the Prime Minister that she did not "consider the significance of this relationship" at the time.