A large group of U.S. states accused key players in the generic drug industry of a broad price-fixing conspiracy, moving on to widen an earlier lawsuit to add many more drugmakers and medicines.

According to the Reuters Health report, the lawsuit, brought by the attorneys general of 45 states and the District of Columbia, accused 18 companies and subsidiaries and named 15 medicines. It also targeted two individual executives: Rajiv Malik, president and executive director of Mylan NV, and Satish Mehta, CEO and managing director of India’s Emcure Pharmaceuticals.

The states said the drugmakers and executives divided customers for their drugs among themselves, agreeing that each company would have a certain percentage of the market. The companies sometimes agreed on price increases in advance, the states added.

The states said Malik and Mehta spoke directly to one another to agree on their companies’ shares of the market for a delayed-release version of a common antibiotic, doxycycline hyclate.

“It is our belief that price-fixing is systematic, it is pervasive, and that a culture of collusion exists in the industry,” Connecticut Attorney General George Jepsen, who is leading the case, told a news conference in Hartford.

Mylan said in a statement it had found no evidence of price-fixing by the company or any of its employees, and vowed to defend itself vigorously. Malik, the company’s second-ranking official, has received more than $50 million in compensation over the past three years, last year making more than CEO Heather Bresch. “Mylan has deep faith in the integrity of its president, Rajiv Malik, and stands behind him fully,” the company said.

Two former executives of Emcure’s subsidiary Heritage Pharmaceuticals pleaded guilty in January to federal charges of conspiring to fix prices and divide up the market for doxycycline and the diabetes drug glyburide. The two men, former Heritage president Jason Malek and former chairman and chief executive Jeffrey Glazer, reached a deal with 41 states and territories in which they each agreed to pay $25,000 and cooperate with the state probe.

The original complaint, filed in December, targeted Mylan, Heritage, Aurobindo Pharma USA Inc, Citron Pharma LLC, Mayne Pharma USA Inc and Teva Pharmaceuticals USA Inc.

The states are pressing a new complaint that would add Novartis AG’s unit Sandoz, India-based Sun Pharmaceutical Industries Ltd, Endo International PLC’s unit Par Pharmaceutical, Dr. Reddy’s Laboratories, Apotex Corp, Glenmark Generics Ltd, Lannett Company Inc, Alkem Laboratories Ltd’s unit Ascend Laboratories and Cadila Healthcare Ltd’s unit Zydus Pharmaceuticals Inc.

Teva spokeswoman Denise Bradley said the company denied the allegations. Endo spokeswoman Heather Lubeski said the company would vigorously defend itself against the claims. Other companies did not immediately respond to requests for comment.

The original lawsuit centered on just two medicines, delayed-release doxycycline and glyburide. The price of doxycycline rose from $20 for 500 tablets to $1,849 between October 2013 and May 2014, according to U.S. Senator Amy Klobuchar, a Minnesota Democrat who had been pressing for action on high drug prices.The amended complaint would expand the number of drugs to include glipizide-metformin and glyburide-metformin, which are among the most commonly used diabetes treatments.

Others include: acetazolamide, which is used to treat glaucoma and epilepsy; the antibiotic doxycycline monohydrate; the blood pressure medicine fosinopril; the anti-anxiety medicine meprobamate; and the calcium channel blocking agent nimodipine.