PHOENIX -- Some Maricopa County Sheriff Office bank accounts that are kept separate from normal county funds, are under investigation by the Arizona Attorney General's Office.

CBS 5 obtained bank account summaries that show withdrawals from as little as a few dollars to as much as several thousand dollars.

Records show money was paid to individuals, companies, a church and Sheriff Joe Arpaio.

Unlike normal county bank accounts, these need no approval for expenditures outside the sheriff's office.

Byron Schlomach, chief economist at the conservative Goldwater Institute, said accounts like these that are outside the normal government banking system create questions in the minds of taxpayers.

"There's definitely the appearance of impropriety when you are more or less hiding the funds from the public and county supervisors," Schlomach said.

One of the accounts is the RICO fund that contains money from property confiscated from criminal activity.

The other is the Jail Enhancement Fund, which is supposed to be used to increase the value, quality, desirability or attractiveness of county jail services or operations.

According to JEF Guidelines and state law, the money is supposed to be deposited with the county treasurer. But that's not happening in Maricopa County.

Critics point to a sheriff's office inmate transport bus as an example of what can happen when county officials don't have a say in purchases.

The bus cost nearly half a million dollars, which is almost three times the price of the buses MCSO has used for years.

County officials had denied the bus request before but the sheriff used JEF funds to make the purchase anyway.

CBS 5 has learned investigators from the state attorney general's office are looking over these same bank account records.

Advocates of open government say outside bank accounts like these simply make government spending less transparent.

"That's what we really need at all levels of government is full transparency where we see every expenditure," Schlomach said. "We know exactly what it's been used for. We know how it's been accounted for."

The sheriff's office refused a CBS 5 News request for an on-camera interview but in an e-mail, a spokesperson writes that these accounts are audited every year by the state auditor general's office and MCSO contends they have the authority to administer these funds.