CoStar is sparing no expense in its latest copyright lawsuit.

The DC-based commercial real estate data firm expects to spend up to $20M this year on the lawsuit it brought against competitor Xceligent in December, The Real Deal reports. CoStar already spent $3M on the suit in Q1 and expects to spend at least $4M in Q2, the company's chief financial officer said on a recent earnings call.

In the lawsuit, CoStar alleges its competitor stole and resold copyrighted data and photos more than 9,000 times. The suit comes as Xceligent is preparing to launch in New York City.

Xceligent CEO Doug Curry called the lawsuit "entirely without merit" after it was filed.

This is not the first instance of CoStar suing its competition for copyright infringement. The firm won a legal battle in March in which a federal judge ordered Apartment Hunters to pay $10K for each stolen listing and image. Another previous litigation target, RealMassive, settled for $1M, which its CEO said was "cheaper than litigating."

Some real estate data experts think firms should share proprietary data in order to increase efficiency and activity in the market. CoStar seemingly disagrees and is willing to pay millions to keep its data proprietary.

CORRECTION, MAY 4, 10:40 A.M. ET: A previous version of this story inaccurately cited the dollar value of CoStar's allegation against Xceligent. This story has been updated.