Four advertisers pulled out of TLC's reality show 19 Kids and Counting, putting pressure on the US cable network to decide the fate of the top-rated programme about a Christian family after reports that the eldest son had molested underage girls.

Retailers Walgreen Co and Payless Shoesource Inc, and hotel chain group Choice Hotels International Inc on Tuesday followed the lead of General Mills Inc in removing their ads from the program.

TLC, which is owned by Discovery Communications, had pulled episodes of the show last week and said Tuesday it had no comment on whether it would cancel the show.

Some of the advertisers took to Twitter to address consumer complaints.

"We share your concerns and we have decided to remove our advertising from the show," said Choice Hotels, which runs Comfort Inn and Econo Lodge chains, among others.

The network pulled all episodes after In Touch magazine last week published information that Josh Duggar, now 27, had molested several female minors when he was a teen.

Duggar issued an apology on Thursday acknowledging "wrongdoing" 12 years ago and quit his job at the Family Research Council, a Christian lobbying group. But he did not directly address the allegations.

The controversy over the Duggars, an Arkansas family of devout Christians, has spilled into the political realm as conservatives rallied to the family's side.

Parents Jim Bob and Michelle Duggar have become popular among conservatives for embodying an honest family struggling to raise 19 kids with wholesome values.

Former Arkansas governor and US presidential hopeful Mike Huckabee came out in support of the family on Friday, while several petitions circulated asking TLC to cancel the program.

The show has been on the air since 2008 and finished its most recent season in May. It is not in production and it is unclear when a new season was scheduled to begin filming.

The most recent season averaged 3.5 million viewers per episode, down from 3.9 million the previous season, according to figures from Nielsen.

With such a devoted following, TLC may take its time to decide the program's fate, said Jeff McCall, a media studies professor at DePauw University in Indiana.

"Right now there may be a lot of outrage, a lot of concern," said McCall. "On the other hand, the American audience is pretty forgiving."

TLC could take weeks or months working with advertisers behind the scenes to find a palatable future for the program, he said.