Denver District Attorney Mitch Morrissey's office confirmed Monday it had launched a criminal investigation of Secretary of State Scott Gessler on the same afternoon the Colorado Independent Ethics Commission voted to begin an investigation into whether Gessler violated the law by using state funds to attend a partisan event.

The commission, on a 4-0 vote, decided that the complaint filed by liberal-leaning Colorado Ethics Watch against Gessler, a Republican who is the swing state's chief elections administrator, was "not frivolous" and should be investigated by staff. The commission also decided to investigate a separate complaint by Colorado Ethics Watch that Gessler improperly took money from his office's discretionary account.

In an e-mail statement to The Denver Post, Morrissey's office spokesman Lynn Kimbrough confirmed that a criminal probe also had been launched.

"There is now a formal criminal investigation into the allegations," Kimbrough said.

Gessler was unavailable for comment, but his spokesman, Rich Coolidge, said, "We welcome a thorough review."

In August, Gessler attended a Republican National Lawyers Association meeting in Sarasota, Fla., and then traveled to the Republican National Convention in Tampa.

Gessler was reimbursed $1,452 from his office's discretionary account for the trip, which was submitted to his office as "RNLA/RNC Trip." His office also paid $422 out of its regular budget for a flight change to bring him home a day early, something he said was needed because of threats against his family.

Gessler, who has been criticized for how he has used his discretionary fund, also sought and received $1,400 from the fund in July 2011 at the end of the 2010-11 fiscal year. The request, for which Gessler submitted no receipts, drained what was left in the fund that year.

Colorado Ethics Watch said it couldn't file a complaint with the commission over that action because it was beyond the one-year statute of limitations. However, the group did file a complaint with the commission over a $117 payout — also with no receipts — Gessler took from the fund in July this year, well within the statute of limitations.

The commission also agreed 4-0 to investigate that action.

Ethics Watch has asked Morrissey, a Democrat, to conduct a criminal investigation into whether Gessler misused state funds.

"Public funds are not for personal or political use," said Luis Toro, director of Colorado Ethics Watch. "We expect the Ethics Commission to conduct a thorough investigation and make it clear that abuse of public funds will not be tolerated in Colorado."

The commission's next step is to ask Gessler to respond to the allegations within 30 days. The matter may be set for a hearing before the commission, which could fine Gessler for twice the amount of funds it determines have been misused.

The commission is a five-member panel that can be composed of no more than two Democrats and two Republicans and must have at least one unaffiliated member. The current commission has two Republicans, one Democrat and one unaffiliated member.

One seat has been vacant since December 2011.

Tim Hoover: 303-954-1626, thoover@denverpost.com or twitter.com/timhoover