The Texas attorney general’s office has hired three consultants for a multi-state probe it is leading into Google, including an economist who worked with some of the firm’s major rivals and a lawyer who is a Microsoft veteran.

A group of 48 state attorneys general, joined by Washington, DC, and Puerto Rico, announced this month that they were investigating accusations of antitrust violations by search and advertising giant Google, one of several focused on tech firms.

The three consultants are Roger Alford, until this year an assistant attorney general in the Justice Department’s antitrust division; Eugene Burrus, an external adviser at McKinsey & Co. who was assistant general counsel at Microsoft; and Cristina Caffarra, an economist heading the European competition team at consultancy Charles River Associates.

“Everyone knows this will be a long-running investigation,” said Alford, who has taught law at the University of Notre Dame since 2012. He told Reuters that meetings on the matter began in August, but declined to comment further.

Texas’ contracts with Alford and Burrus — obtained by Reuters on Wednesday through a public records request — ran from May 29 through Aug. 31, with a maximum hourly fee of $500 and an optional extension. Alford said his contract had been extended through Aug. 31, 2021.

Caffarra’s contract runs from Sept. 3 to Aug. 31, 2021.

Burrus, Caffarra and the Texas attorney general’s office did not respond to requests for comment. Google, which has said it is cooperating with investigators, declined to comment.

Burrus spent 15 years at Microsoft before joining law firm Hagens Berman Sobol Shapiro in 2017 for a short stint. It has represented clients in antitrust and other lawsuits against Google, and his firm biography says he developed an antitrust case that led the EU to fine Google $2.7 billion for its shopping tool in 2017.

A spokesman for Microsoft, which has complained about Google’s competitive tactics, did not provide immediate comment.

Caffarra, standing among several attorneys general this month at a news conference for the Google investigation, posted on Twitter that the announcement was “a huge deal.”

Alford said he was also at the event.

The Federal Trade Commission and several states led by New York’s attorney general have confirmed antitrust investigations into Facebook.

The FTC is also looking at Amazon, sources have said. The Justice Department has launched a broad review of large internet companies.