DENVER — Colorado state treasurer Walker Stapleton cited the possibility of fraud in the collection of voter signatures when he announced on Tuesday that he will try to qualify for the Republican gubernatorial primary at the party’s assembly this weekend.

Stapleton will join Attorney General Cynthia Coffman and Colorado Springs businessman Barry Farah in trying to qualify at Saturday’s GOP state assembly. Each needs at least 30 percent of delegate votes to advance to the June 26 primary.

Colorado’s Democratic Gov. John Hickenlooper is term-limited and cannot seek reelection.

Stapleton asked Secretary of State Wayne Williams to disregard voter signatures that were submitted by his campaign and that had been deemed sufficient by Williams to qualify for the ballot, KMGH-TV reported .

The two-term treasurer cited concerns about fraud by a Colorado Springs-based firm that his campaign had hired to gather the signatures.

The firm, Kennedy Enterprises, didn’t immediately respond to telephone calls from The Associated Press for comment.

In a letter to Williams, Stapleton cited KMGH-TV reports about allegations that a signature gatherer hired by Kennedy Enterprises had circulated petitions under the guise of being a different person.

Stapleton asked Williams’ office to investigate. Williams’ office had no immediate comment.

Other GOP gubernatorial contenders include businessmen Doug Robinson and Vic Mitchell, who have turned in signatures to make the ballot.