Conservative Party co-chairman Baroness Warsi was guilty of only a "minor" breach of the ministerial code in relation to a trip to Pakistan with a business partner, the Prime Minister's adviser on ministerial interests has ruled.

Sir Alex Allan said Lady Warsi accepted that she should have informed officials of her relationship with Abid Hussain - a second cousin of her husband - and had already issued an apology.

David Cameron said he was satisfied that Sir Alex's report found that she did not at any point use her office for any personal financial gain.

Sir Alex said that when he interviewed Lady Warsi a number of "related issues" arose - including her wish for clearer guidance on travelling with spouses.

"Baroness Warsi's office was clearly stretched when it came to handling arrangements for overseas travel, especially given that her overseas visits tend to involve issues and arrangements which are out of the ordinary for regular departmental ministers," he said.

"I therefore recommend that the Cabinet Office and the Foreign Office should discuss and agree arrangements for providing advice and support to Baroness Warsi in relation to the ministerial code."

Lady Warsi said in a statement: "I have always maintained that I have never misused my ministerial office for personal or financial gain.

"The allegations on this matter were untrue and unsubstantiated and I am pleased that Sir Alex Allan's report has confirmed that.

"The last month has been a difficult time for me and my family and I am pleased I can now move on from this period and get on with the job that I am privileged to do."