*Editor's note: This story has been updated with comment from a spokesman for Ken Paxton.
The move comes amid swirling questions around how Collin County prosecutors would handle the case, given the fact that Willis is a friend and business associate of Paxton's. The statement from Willis' office came a day after news reports that a Collin County grand jury was interested in Paxton's case.
In January, the Travis County district attorney's office closed its investigation of Paxton without bringing charges, saying the office lacked jurisdiction. At the time, Travis County District Attorney Rosemary Lehmberg said the appropriate venues for Paxton's potential prosecution would be Collin and Dallas counties, where he had admitted to breaking the law.
While Paxton was running for attorney general last year, he was fined $1,000 for failing to register with the State Securities Board while soliciting clients for investment firms.
The liberal Austin-based watchdog group Texans for Public Justice sought to jump-start the case in Collin County on Monday, calling on Willis to recuse himself and appoint a special prosecutor. The group said the move was necessary because of Willis' relationship with Paxton.
A Dallas-area attorney on Wednesday disclosed a letter purporting to show a member of a Collin County grand jury requesting information on Paxton from the Travis County district attorney's office.
That letter was first revealed by the Houston Chronicle.
The Collin County district attorney's office confirmed Thursday it had received a complaint from a "political group." The allegations in the complaint, Willis' office said, were similar to those recently passed along by Travis County prosecutors.
"Our office took steps to have appropriate investigative agencies, including the Texas Rangers, follow up on those allegations," Willis' office said in the statement. "To facilitate this process, we have today requested Travis County’s files for law enforcement."
Later Thursday, Paxton spokesman Anthony Holm drew attention to another part of Willis’ statement that emphasized the Collin County district attorney’s office has not received a case from any agency, including the one that dealt with Paxton’s violation.
“The State Securities Board did not refer a criminal case to any county, because there isn’t a criminal case to refer,” Holm said in a statement. “The Texas Rangers have a storied history of professionalism and integrity, and we have full confidence in their abilities and acumen.”