A San Diego County Sheriff's sergeant said on Wednesday that the investigation into Vista City Councilman Frank Lopez's business practices uncovered at least 656 bad checks written between 2004 and 2009 on bank accounts for his Mexican restaurant.

The checks were written from nine accounts at three Vista banks and totaled $185,477, said Sgt. Mark Varnau. Many of the checks were to restaurant employees and vendors.

The number of bounced checks is more than six times the roughly 100 initially reported by authorities last year.

After a yearlong investigation, authorities in June charged Lopez and his wife, Mary, with a misdemeanor, alleging that they failed to pay workers' compensation insurance for employees at their Casa Linda Mexican restaurant on South Santa Fe Avenue in Vista.

Officials with the district attorney's office said last month that they couldn't charge the couple with check fraud because they couldn't prove Lopez intended to defraud anybody.

Deputy district attorney Anna Winn, who initially handled the case, told the North County Times earlier this month that prosecutors were limited because it was difficult to determine whether the Vista banks that held Lopez's accounts, California Community Bank and Pacific Western Bank, immediately notified him in each instance that his checks surpassed his account balances.

Officials with the banks have not returned phone calls seeking comment.

"We only issue cases we are 100 percent confident we can prove beyond a reasonable doubt," Winn said on July 6. "It's not that he didn't write bad checks, but the law requires more than that. We have to prove beyond a reasonable doubt ... that when the person passed the check, they knew they had no money in their account."

Lopez could not be reached for comment Wednesday. He continues to serve on the council, but has not returned phone calls from reporters for more than a year and has avoided them at public meetings, in one instance saying questions about the matter were "inappropriate."

An answering-machine message at Casa Linda on Wednesday said the restaurant was closed for a summer break. The Lopezes' cell phones have recently been disconnected.

Prompted by employee complaints, the sheriff's department began investigating the Lopezes in early 2009. In June of that year, investigators said the couple was suspected of writing more than 100 bad payroll checks to employees since 2004.

At that time, Sgt. Varnau told the North County Times that search warrants served on at least two Vista banks uncovered about $20,000 in checks drawn on Casa Linda payroll accounts that were returned because of insufficient funds.

Varnau said Wednesday that more warrants were served as the investigation continued and more bad checks were discovered.

He said $13,401 in fees were charged additionally on the accounts for checks returned for insufficient funds.

Varnau said the checks were "covered at some point in time."

At a Tuesday night City Council meeting, three residents publicly chastised Lopez for the scandal, while several family members and supporters praised his community service and patriotism.

Lopez, who was elected in 2004 and re-elected in 2008, thanked the supporters, called the scrutiny into his finances "embarrassing" and talked for several minutes about his volunteerism and leadership in city programs.

Call staff writer Cigi Ross at 760-901-4067.