Josh Duggar Josh Duggar

Another member of Josh Duggar's extended family is speaking out after his admission of infidelity. One week after Duggar's brother-in-law announced that he wants "that pig out of our family," his sister Jessa's father-in-law has come out in condemnation of Duggar's actions in a lengthy essay.

Michael Seewald, father of Jessa's husband Ben, is calling Duggar a hypocrite after he confessed that he used the Ashley Madison website to cheat on his wife Anna. Seewald previously supported the family when reports surfaced that Duggar had molested underage girls.

"It distresses me to say that Josh Duggar's greatest sin is a byproduct of the sum total of his secretly sinful lifestyle. That is, that by his hypocrisy, he blasphemed the name of God. He claimed to be a Christian, but by his deeds he has suggested otherwise," Seewald wrote on the family's website. "While proudly saying things like, 'Our family is like the epitome of conservative values,' he was looking at porn and soliciting affairs. He took a job at the Family Research Council that exists to promote the traditional family, all the while undermining his own family by violating his marriage covenant.

Josh Duggar checks into rehab following Ashley Madison scandal

"He flourished in the fame of his family and the success of their television show, all the while betraying their trust and Christian values. The thing that is so hurtful is that he was a loud voice endorsing Christian ethics and he has been shown to be a fraud. I am profoundly grieved that he attained such a platform only to bring shame on God's holy name and the Christian faith," Seewald continued and added that Josh "deceived us all" when he appeared to be a changed man.

Duggar has since checked into a rehab facility in Illinois that offers a treatment program "based solely on the Bible" according to People.

You can read Michael Seewald's full essay here.

VIDEO: Inside Josh Duggar's life at rehab

-shockwave-flash' height='338' width='600'>