(AP) — Authorities are investigating a Texas firm that has been accusing Nebraska businesses of infringing on patents.

Nebraska Attorney General Jon Bruning says Texas law firm Farney Daniels has sent multiple threatening letters to Nebraska businesses.

Bruning says he has ordered Farney Daniels to stop sending letters while his office investigates whether they are deceptive.

Bruning says the law firm appears to represent companies that bought up patents just so they could threaten lawsuits and collect settlements.

A spokesman for the law firm didn’t immediately return a call Friday from The Associated Press. The firm is based in Georgetown, Texas, a suburb north of Austin.