BUFFALO GROVE, Ill. -- Victims are speaking out about allegations of sexual harassment at a Buffalo Grove company.

A federal agency is investigating the allegations and is calling it the largest "current sexual harassment class action" lawsuit. More than 100 people are involved in this case.

The women NBC5's Marion Brooks talked to made graphic allegations, describing instances of sexual harassment alleged against International Profit Associates for more than 10 years. The government described it as one of the worst sexual harassment cases it has seen.

"I had a floor manager who would rub ... on my back as I would sit at my chair and ask for me to give him (oral sex) in the backroom," said Adrienne Slick, one of more than 100 who claim sexual harassment at IPA.

Slick said she experienced the harassment weekly -- sometimes daily -- over the 8 months she worked there.

A woman who lasted 10 months with the company described similar harassment.

"One of the sales managers -- whenever he would see me -- would pin me up against the nearest wall, rub against me and ask if I liked sex," she said.

According to the lawsuit filed by the Equal Employment Opportunity Commission on behalf of the class, the harassment started right at the top. One class member said the CEO offered her money to have sex with him and would regularly ask her for oral sex, which she refused to perform. Lawyers for the class said that set the tone of behavior.

Class members told NBC5 about as many as 60 male employees who have harassed more than 100 women over the course of many years. The women believe management knew about this.

"I tried to tell my manager, but my manager did the same thing and said, 'Sit on my lap and I'll take care of it.'"

After many years, two women finally came forward. The EEOC spent two years investigating and found more victims.

IPA has been listed on Inc Magazine's list of fastest-growing companies. In a 2000 article, its revenue was reported to be more than $100 million. The Daily Herald said IPA has 1,600 employees.

NBC5 could not reach agents with IPA, but in the lawsuit, the company denied all allegations.