Former US reality TV star Josh Duggar has left rehab after a six-month stay triggered by an admission that he cheated on his wife and was addicted to pornography.

Duggar, 28, the eldest child in the "19 Kids and Counting" reality TV show canceled in 2015, will continue to get counseling at home while he rebuilds relationships with his family, the Duggar family said in a statement on its website on Thursday.

"We look to God for help and guidance and place all of our trust in Him. We are forever grateful for the love and prayers offered by so many and hope you will continue to pray in the days ahead," the family said.

Duggar checked into rehab in August 2015 after reports that he was a subscriber to the hacked Ashley Madison affair website. Hackers in August dumped million of email addresses for customers of Ashley Madison, whose tagline is "Life is short. Have an affair."

Duggar, who is married with four children and who formerly worked for the Christian lobbying group Family Research Council, said in August he was "the biggest hypocrite ever."

"The last few years, while publicly stating I was fighting against immorality in our country I was hiding my own personal failures," said Duggar, just before entering rehab.

Three months earlier the Duggar family acknowledged that Josh had molested four of his sisters when he was a teenager and the TLC cable network canceled the long-running "19 Kids and Counting" show about the Duggar clan.

Duggar has resigned from his job at the Family Research Council.