U.S. property management company Greystar swindled renters across the country out of hundreds of millions using deceptive advertising and hidden fees, according to a lawsuit filed Thursday by the U.S.

Colorado Attorney General Phil Weiser and federal regulators filed a joint lawsuit against the largest apartment owner in the country on Thursday, accusing it of intentionally misleading tenants about the cost of its rentals.

The Federal Trade Commission will reportedly allege the apartment management company falsely advertised rental prices by not including mandatory fees.

Colorado and the FTC say Greystar Real Estate and Property fraudulently advertises low rent prices to potential customers, only to add tens if not hundreds to the monthly rent cost with hidden fees.

The complaint filed Thursday charges that the country’s largest landlord failed to include information about numerous mandatory fees in its listings.

Greystarwas sued by the Federal Trade Commission Thursday over allegations that the nationwide manager of apartment buildings, stuck renters with millions of dollars in hidden fees.

Colorado Attorney General Phil Weiser's office says that the suit specifically claims that Greystar uses deceptive advertising practices by failing to mention some mandatory, fixed fees in the advertised price for an apartment.

One of the largest rental companies in the country is facing two separate lawsuits, including from Colorado’s Attorney General, Phil Weiser. He says Greystar is charging local tenants hidden fees.