When you’re looking for an internet service provider, you want to know if they offer the most up-to-date, fastest broadband speeds. But if the New York attorney general is right, you may not be getting the internet connection that you’re paying for.

Last week, New York’s attorney general Eric Schneiderman sent letters to three leading telecommunications company, requesting information about their broadband services, according to Reuters. The letters sent to Verizon, Cablevision Systems and Time Warner Cable ask the companies to provide the disclosures they share with customers and any testing data they use to verify their broadband speeds.

The investigation was prompted by consumer complaints and a 2014 study that found discrepancies between advertised broadband speeds and the actual internet connection in independent testing. The study suggested that broadband speeds would slow when internet service providers lines connected with long haul traffic carriers.

These “interconnection arrangements” between the broadband companies and the long haul networks are expected to be a focus of the investigation. The 2014 study found that such interconnections can have severe negative impacts on the broadband connection delivered to consumers.

Verizon did not comment on the investigation; the other two companies stood by their offerings and stated they would comply with the attorney general’s requests for information.