By Brian Maass

DENVER (CBS4)– The day after CBS4 revealed a Denver grand jury is investigating Colorado Secretary of State Wayne Williams over alleged campaign finance irregularities; Williams said he was “disappointed” the Denver District Attorney plans to continue investigating how his office handles campaign finance complaints.

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The grand jury began meeting this month.

(credit: CBS)

Ken Lane, a spokesperson for Denver District Attorney Beth McCann, confirmed that there was an open investigation in the Denver grand jury relating to Williams and his office.

CBS4 Investigator Brian Maass interviews Sec. of State Wayne Williams (credit: CBS)

In an on-camera interview Thursday with CBS4 Investigator Brian Maass, Williams said he wasn’t overly concerned about the grand jury probe.

CBS4 INVESTIGATION: Grand Jury Investigating Secretary Of State Wayne Williams

”I am not because I believe that everything we’ve done has followed Colorado law.”

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Matt Arnold (credit: CBS)

On Friday, Williams released this statement regarding the investigation, “This is why legitimate debate about our campaign finance law should happen in public at the legislature and not behind closed doors in secret proceedings.”

The probe was sparked by complaints filed with the DA’s office by Matt Arnold, a longtime Republican who runs the website Campaign Integrity Watchdog.

(credit: CBS)

Williams and Deputy Secretary of State Suzanne Staiert have both received subpoenas to appear before the Denver grand jury on April 11.

There is no timeline on the length of the grand jury investigation.

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CBS4 Investigator Brian Maass has been with the station more than 30 years uncovering waste, fraud and corruption. Follow him on Twitter @Briancbs4.