WASHINGTON (NEXSTAR) — Senator Richard Blumenthal (D-CT) is accusing Live Nation of trying to cover up what he calls their predatory policies.

“Consumers are sick and tired of astronomic ticket prices, hidden fees,” Blumenthal said.

The Connecticut Democrat’s subcommittee launched an investigation last November, after the demand for Taylor Swift’s Eras concert tour caused Live Nation’s Ticketmaster website to crash, which drew attention to other problems within the ticket industry.

“People deserve to know whether these predatory practices are the result of monopolistic misuse of power,” Blumenthal added.

After the concert giant refused to hand over requested information, Blumenthal’s subcommittee issued a subpoena for documents he says are critical to the investigation.

“Relating to fee setting policies, ticket charges, relationships to artists and venues,” Blumenthal said.

Senators say Live Nation and Ticketmaster control over 80% of all ticket sales in the U.S. and the majority of venues.

At a hearing in January, the C.E.O. of SeatGeek told senators the solution is clear.

“Venues fear losing Live Nation concerts if they don’t use Ticketmaster. The only way to restore competition in this industry is to break up Ticketmaster and Live Nation,” Jack Groetzinger said.

Blumenthal says he hopes to wrap up his investigation by the end of this year.