SAN ANTONIO - Federal agents took over the local law office of Senator Carlos Uresti Thursday morning.

Agents blocked access to the office building in the 900 block of McCullough with crime scene tape and could be seen most of the day moving about with boxes of potential evidence.

A mobile computer forensics van and several other large vehicles were present at the office building.

“The FBI and IRS are lawfully present conducting a law-enforcement activity at the location,” the local FBI spokesman said.

In a statement issued late Thursday morning, Senator Uresti said he instructed his staff to cooperate fully with the investigation.

Uresti said investigators were looking for information about what he called "the FourWinds matter." He admitted they were involved in a broad investigation of his role in a failed oil field fracking sand business.

FourWinds Logistics has been in bankruptcy court and could be facing millions of dollars in claims.

Uresti has been publicly linked to the company and it appeared investigators were looking into exactly what his role may have been.

In addition to full cooperation, Uresti said he will continue his role in the Senate, committed to serving his constituents.

Here is the full statement issued by Senator Carlos Uresti:

"Today, FBI agents are in my office, reviewing our documents as part of their broad investigation of the Four Winds matter. I have instructed my staff to fully cooperate with the federal investigators. I will help them in whatever way I can.

"I am now at the Capitol conducting the people's business, working hard to achieve a good budget for the people of Texas through my continued service on the Senate Finance Committee, and to find solutions for the foster children of Texas, as the Vice-Chair of the Health and Human Services Committee. Likewise, I continue to work diligently to solve problems on the Veterans Affairs and Border Security Committees.

"As always, I remain committed to serve my constituents."