The competition watchdog has launched an investigation into drug companies accused of charging the NHS excessive prices.
If the companies are found by the the Competition and Markets Authority to have broken the law, they could face fines of up to 10% of their turnover.
The CMA said: “The investigation relates to suspected unfair pricing by way of charging excessive prices in the supply of certain pharmaceutical products, including to the National Health Service.”
The health secretary, Jeremy Hunt, called in the CMA in June after an investigation by the Times suggested companies were exploiting a loophole in NHS rules to raise prices of medicines.
The newspaper alleged that companies faced limited competition on long-established, off-patent drugs, bought from large pharmaceutical firms. It was also claimed that the prices of 32 drugs had risen by more than 1,000% in the past five years.
Concordia International said it was one of the companies being investigated. A spokesman said: “We are working cooperatively to better understand the CMA’s position and we will continue to work constructively to resolve the matter.
“Although Concordia has also had past discussions with the CMA regarding the supply of certain of its products in the UK, this is the first interaction with the CMA regarding the company’s pricing.”