One of the most prominent members of the Westboro Baptist church has left it after spending her life as part of the fervently anti-gay movement.

Megan Phelps-Roper, who looked after social media for the church best known for its slogan "God hates fags", announced her departure in a post on the blogging platform Medium in which she also revealed her younger sister Grace, 19, was also leaving.

In the post, called Head Full of Doubt/Road Full of Promise, the 27-year-old explained how she had become disillusioned with the teaching of Westboro, which is widely considered one of the most detested church groups in America for its "God hates fags" campaign.

Phelps-Roper writes: "We know that we've done and said things that hurt people. Inflicting pain on others wasn't the goal, but it was one of the outcomes. We wish it weren't so, and regret that hurt.

"We know that we dearly love our family. They now consider us betrayers, and we are cut off from their lives, but we know they are well-intentioned. We will never not love them.

"We know that we can't undo our whole lives. We can't even say we'd want to if we could; we are who we are because of all the experiences that brought us to this point. What we can do is try to find a better way to live from here on. That's our focus."