A fundamentalist Christian ministry attended by Josh Duggar has been accused of enabling and covering up the sexual abuse and harassment of employees and children involved in its programmes.

Five women filed a lawsuit on Tuesday against the Institute in Basic Life Principles (IBLP), once a leader in the Christian home-schooling movement, accusing the board of directors of wilfully engaging in a conspiracy to conceal abuse, according to The Washington Post.

It charges that employees and directors "frequently received reports" of "sexual abuse, sexual harassment and inappropriate/unauthorised touching." These "serious, potentially criminal allegations [were never reported] to law enforcement authorities or the Illinois Department of Children and Family Services" as required by state law.

IBLP, based in Illinois, describes itself as an organisation providing "clear instruction and training on how to find success by following God's principles found in Scripture." It was once admired by conservative Christian parents for its teaching materials and programmes that focus on 'Biblical character' development.

David Gibbs III, the attorney representing the women who filed the lawsuit, told the Washington Post that the alleged victims had hoped to address the issue with the IBLP board of directors, but were forced to litigate after the board "rather stubbornly and in my opinion rather arrogantly basically challenged the girls to bring the case".

The board, he said, "is not operating in a spirit of transparency or openness," and has not discussed the allegations with the women.

The lawsuit, where each complainant is seeking $50,000 in compensation, follows IBLP's founder, Bill Gothard's, resignation after a number of allegations of sexual harassment were made.

Recovering Grace, a website created by former followers of IBLP, has compiled stories of more than 30 women who have said they were sexually groomed and inappropriately touched by Gothard over a thirty year period.

They sought to address the charges internally, but Gothard, 80, denied the allegations and an internal investigation reported "no criminal activity has been discovered," but that "Mr. Gothard has acted in an inappropriate manner."

Gibbs has said that victims were as young as 13 or 14 years old, and were often abused at home in varying degrees. The "pattern" common among the claimants, he said, was that the girl would "act out" after abuse at home and she would be sent to IBLP for counselling.

There are other claims that Gothard would ask sexual assault victims during counselling whether they had been dressed immodestly at the time of the attack. He also taught that unless a victim had cried out to God to stop the assault, she was equally guilty with her assailant.

Speaking to the Washington Post, Gibbs said that Gothard would abuse the girls himself, and if they rejected his advances, Gothard or another IBLP leader would "call the parents and share with them all the allegations of abuse that were shared in counselling, and then send the children back into those environments".

A spokesperson from Recovering Grace, John Cornish, said of the lawsuit: "Our goal and our hope is the same as it's been all along — that they will be accountable for what's taken place, that Bill [Gothard] and the board would repent, and that the victims will finally be acknowledged and taken care of in the right manner."

According to reports, the Duggar family have supported and been involved in the IBLP ministry. It was recently reported in In Touch magazine that Josh Duggar had been sent to its training centre as a teenager after he admitted to sexually abusing his four younger sisters and a family friend.