Northern Ireland's Deputy First Minister Martin McGuinness raised a few laughs - and perhaps just as many eyebrows - when he revealed he had slept in the Queen's bed at Hillsborough Castle.

Mr McGuinness, a former IRA leader, told the story during an after dinner speech at the 18th century castle, the Queen's official residence in Northern Ireland.

Hillsborough was used during hot-house political talks in 2010 over the transfer of policing powers to Stormont from Westminster.

Mr McGuinness told 150 delegates attending a gala opening of the international business conference that Sinn Féin was assigned the Queen's bedroom during days of negotiations with the Government.

"We were lucky enough that we were allocated the Queen's bedroom," he said, causing an outbreak of chuckling among the audience.

"I do not want you to tell anybody ... "

Cue more laughter.

"But I had a snooze in her bed," smiled Mr McGuinness, before adding: "She was not in it, so no scandal attached."

With the TV cameras focused on Mr McGuinness, the reaction of some of those in the room, including First Minister Peter Robinson and Secretary of State Theresa Villiers, is not recorded.

It is also unclear if one was not amused at Buckingham Palace ...