GG's officer reveals resignation reason

Governor-General Quentin Bryce was considering the integrity of her office when she offered to resign in October 2013, a Senate committee has heard.

Prime Minister Tony Abbott last year revealed Ms Bryce had offered to resign in anticipation of Bill Shorten's election as Labor leader.

Ms Bryce is Mr Shorten's mother-in-law.

Mr Abbott at the time thanked Ms Bryce for her magnanimity, but declined to accept her resignation.

Ms Bryce's official secretary Stephen Brady told a Senate estimates hearing on Monday he had personally conveyed the offer of resignation to Mr Abbott's chief of staff Peta Credlin.

"She did so out of an abundance of caution so that the prime minister knew that she placed the integrity of her office above all else," Mr Brady said.

Ms Bryce will retire in late March when former military chief Peter Cosgrove takes over the role.

The committee also heard that the Duke and Duchess of Cambridge's private secretaries had recently visited Australia to conduct planning for what would be a "very extensive visit" to Australia.