Longtime Maricopa County Supervisor Don Stapley has been indicted on more than 100 felony and misdemeanor counts stemming from a suspected failure to disclose interests in millions of dollars worth of property and other business dealings.

A joint investigation by the Maricopa County Attorney's and Sheriff's offices alleged that Stapley failed to disclose millions of dollars of loans, hundreds of thousands of dollars in deposits from checking accounts into business accounts, real-estate deals in Pinal County, and other assets. The investigation reportedly turned up irregularities in Stapley's financial-disclosure forms going back to 1994.

For example, the County Attorney's Office said that Stapley also failed to reveal a bankruptcy by one of his companies and that the assets listed on a 2006 loan application varied from the assets he listed on his 2006-07 financial-disclosure form.

Under state law, government officials must complete annual financial-disclosure statements.

On Nov. 20, a Maricopa County grand jury handed up an indictment on 118 counts, including perjury, forgery, false swearing (all felonies) and filing an incomplete and/or false financial-disclosure form, a misdemeanor.

Stapley was out of the country and was not served with the indictment until Tuesday. He is scheduled to be arraigned Thursday.

"The allegations all pertain to non-disclosure at this time," County Attorney Andrew Thomas said. "We don't have all the answers yet. The sheriff doesn't, either. But we made a commitment to get to the bottom of this."

Thomas' office sought to have Stapley arrested, but a Maricopa County Superior Court commissioner refused to issue a warrant.

Thomas and Sheriff Joe Arpaio want to investigate whether any conflicts of interest occurred with the land parcels in question. In his role as a county supervisor, Stapley makes decisions on land developments, rights of way and purchases of county property.

Also of concern was the potential participation of a felon who was an associate of Stapley.

Arpaio was concerned about whether other county employees tipped Stapley to the investigation. Arpaio said that after deputies questioned employees in the county Board of Supervisors office and asked them to keep the matter confidential, Stapley filed amended disclosure forms.

"We are going to pursue any cover-ups in the case," Arpaio said.

Stapley did not return calls but released a statement through his attorney.

"I have served in public office for 14 years," he said.

"I'm proud of that service. I have always put the interest of the public first, including full and complete disclosure of any assets. I stand falsely accused of failure to disclose financial information. I have disclosed all the information and income required by law during my time in office. I am shocked and disappointed that such accusations are being made. I cannot fathom where these accusations came from or what motivated them, but if my integrity is being questioned, I assure you that I stand on my record of complete integrity and disclosure and will fight these allegations. This matter should be quickly dismissed."

Stapley's family has been in the Phoenix area for 130 years.

A Republican, he was first elected to the Board of Supervisors in 1994 to represent Scottsdale, Mesa, Paradise Valley, Gilbert and parts of Phoenix. He has risen to national prominence during his 14 years in office.

He is president of the National Association of Counties, which represents more than 2,000 county governments.

"We fully expect that he will continue to lead our association . . . in the months and years ahead," association representative Jim Phillips said Tuesday.

Stapley has come under scrutiny before for his real-estate dealings.

He became a licensed real-estate agent in 1995. Then, in 1997, he was the target of an Arizona Department of Real Estate investigation during his first term as a Maricopa County supervisor.

The department accused Stapley and others of illegally splitting acreage in the Santan foothills south of Queen Creek into smaller parcels for profit.

The practice carves up land without providing for adequate roads and utilities and violates Arizona laws designed to prevent haphazard development.

Three years later, in 2000, the Department of Real Estate charged his associates in the land deal with land-splitting violations but did not charge Stapley.

The current investigation began earlier this year after a confidential tip to the County Attorney's Office. Thomas stressed that the investigation is ongoing.

He and Arpaio, both Republicans, said there are no political overtones to the investigation or the indictment.

"It's sad sometimes when you have to do things against county officials you deal with every day," Arpaio said. "We have to do our job. No one is immune."

Republic reporters Edythe Jensen, Catherine Reagor and JJ Hensley contributed to this article.