There were three letters leaked:
One from 4 April 2016, which was Rudd's formal nomination for the position. The letter referred to "support you have offered me in our discussions on my candidature".
One from 1 May 2016, which asked Turnbull to reconsider his position after a phone call between the two men. Rudd also said in the letter, "as you know we have had many discussions in person, by text and by phone on the matter of my candidature".
One from 28 July 2016, which asked for a private meeting between the two ahead of Turnbull's final decision.