Dr Williams contrasted his views as theologian and church leader
Private letters have been published revealing Archbishop of Canterbury Dr Rowan Williams believed gay sexual bonds were "comparable to marriage".
The correspondence, written in 2000 and 2001, said gay partnerships may reflect God's love like marriage if they showed "absolute covenanted faithfulness".
But the Anglican Communion's orthodox position opposes active homosexuality.
Lambeth Palace pointed out that Dr Williams committed himself to this position last month.
The revelations threaten to reopen bitter divisions over the issue of gay bishops, which pushed the Anglican Communion towards a split and led 250 clergy to boycott the recent Lambeth conference.
The exchange of letters with an evangelical Christian, written when Dr Williams was Archbishop of Wales, described his "definite" belief that biblical passages criticising homosexual sex were not aimed at people who were gay by nature.
But in the letters, Dr Williams drew a distinction between his own beliefs as a theologian and his position as a church leader, for which he had to take account of the traditional and majority view.
And he wrote of his regret that the issue was "very much politicised" and treated by many as “the sole or primary marker of Christian orthodoxy”.
The letters were written in response to a challenge from Deborah Pitt, a psychiatrist and evangelical Christian living in his former diocese in South Wales.
But Lambeth Palace said Dr Williams had made his views on the issue of homosexuality clear at a press conference on 21 July 2008.
"The Anglican Communion has made its position corporately clear through the Lambeth conference and through all the things we have been going through in recent years. As Archbishop of Canterbury that is where I stand, and that is the position I am committed to stand with," he added.