ANNAPOLIS, Md. (AP) — Maryland uncovered a massive criminal enterprise involving identity theft and more than 47,500 fraudulent unemployment insurance claims in the state adding up to more than $501 million, Gov. Larry Hogan said Wednesday, saying the case relates to activity in at least a dozen other states.

The governor announced at a news conference that employees at the state’s unemployment insurance website detected an unusual increase in out-of-state federal pandemic unemployment assistance claims and reported it to federal authorities.

“It is obviously a coordinated criminal enterprise because this is not just random people in their basement that stole somebody’s identity,” Hogan said.

Maryland Labor Department Secretary Tiffany Robinson said the activity was found by employees over the Fourth of July weekend.

“With heightened security measures in place, our department quickly detected, reported, and blocked this fraudulent claim activity, saving taxpayers hundreds of millions of dollars,” Robinson said.

“We will continue to work with our state and federal partners to prevent fraudsters from capitalizing upon the hardships caused by the coronavirus during these already difficult and uncertain times.”

Derek Pickle, acting special agent-in-charge of the Office of the Inspector General at the U.S. Department of Labor, said the nation has seen a dramatic increase in the amount of unemployment insurance fraud around the nation during the coronavirus pandemic, which has caused unprecedented challenges for states trying to process unemployment claims.

“To give you a sense of how that spike corresponds to our work, unemployment insurance fraud investigations have historically made up approximately 10% of our agency’s investigative workload,” Pickle said at the news conference. “Today more than 50% of our investigative matters pertain to unemployment insurance and that number continues to grow by the day and that includes investigative matters in all 50 states.”

Maryland’s labor department is coordinating with the U.S. attorney’s office and the U.S. Labor Department of Labor’s Office of Inspector General to investigate.

“My office and the entire law enforcement community are committed to bringing to justice fraudsters who are preying on citizens during this unprecedented public health crisis by using their stolen personal information to fraudulently attempt to obtain unemployment benefits,” Maryland U.S. Attorney Robert Hur said in a statement.