Investigators reviewing 58 Atlanta schools for possible cheating on state tests said Tuesday they continue to pursue tips and information that are important to their inquiry.

That work, coupled with ongoing analysis of students’ most recent test scores, is the reason a special investigative panel delayed completion of its probe. The panel’s chairman said last week that as many as 100 employees at 12 schools may be reported for possible violations of test security procedures.

Neither the board or its investigator discussed many details of the additional information.

The independent panel formed to look into irregularities on state standardized tests at city schools met as scheduled Tuesday morning. But instead of releasing a report on its investigation, which the board said is still weeks away, panel members heard an update from lead investigator Charles Riepenhoff of the auditing company KPMG.

Riepenhoff said tips have increased slightly in the past few weeks. The panel established a hotline phone number and calls to that line were one source of the additional information.

Investigators have interviewed more than 280 city school employees — 20 more than in early June. Seventeen employees have been interviewed more than once. Other “re-interviews,” Riepenhoff said, are scheduled. Investigators have also talked to 12 to 15 non-employees, including parents and students.

They have looked at more than 53,000 e-mails sent and received within the city school system this year and last — a number double that of a few weeks ago.

“We know how important [the report] is,” said Gary Price, the panel’s chairman and a partner with PricewaterhouseCoopers. “We are committed to getting this done as quickly as we can” without sacrificing accuracy, Price said.

Officials with Atlanta Public Schools declined to comment on the meeting. City schools Superintendent Beverly Hall in a statement last week reiterated her support of the investigation and said “cheating of any form undermines our goals, will not be tolerated and will be dealt with swiftly and thoroughly.”

According to a state audit released in February, 191 Georgia public schools in 34 systems required investigation because they showed unusual patterns of erasures on the state’s 2009 Criterion-Referenced Competency Tests. The tests, of students in first through eighth grade, help determine whether schools meet federal benchmarks.

Atlanta had the most schools flagged in any system, more than two-thirds of its public elementary and middle schools. Atlanta school board members sought help, which resulted in the investigation of those schools with oversight by the 15-member panel of city business and community leaders.

Atlanta is the only system that has not turned in its investigative report, which was originally due in late May. The state granted a request by the panel for an extension, with a soft deadline of mid-June.

Kathleen Mathers, executive director of the Governor’s Office of Student Achievement, which did the audit, said Tuesday that while her office did not “want this to go on indefinitely,” she supported having a complete, high-quality report over a rush to get it done.

Mathers also said Price, as the panel’s representative, has been in regular communication with her about the Atlanta investigation.

“We have emphasized that it’s not 12 schools we have concerns about, but all 58,” Mathers said.

Price said the report will be comprehensive. According to investigators, the panel prioritized work involving the 12 Atlanta schools due to multiple red flags, including the number of erasures, inconsistent scoring or unusual grade increases.

The group said they had moderate to minimal concerns about the other 46 city schools. Those schools were reviewed but while the report may make recommendations involving some of them, but there is no indication employees at those remaining schools will be implicated.

Price told The Atlanta Journal-Constitution last week that as many as 100 city school employees at the 12 schools will be referred but did not detail the violations, which could range from inadvertently breaking test security rules to outright cheating.

He has also declined to name the schools where these employees work, although school names will be included in the report, he said.

The panel on Tuesday held a two-and-a-half-hour closed session to talk about personnel issued related to the investigation. Afterward, Price said the panel would not speculate or comment until the report is finished in “weeks.”

That lack of specifics angered John Sherman, president of the Fulton County Taxpayers Foundation, who said he has collected more than 1,200 signatures on a petition seeking Hall’s resignation if the investigation confirms teachers cheated.

“It’s still being dragged on,” he said.

Who to call

The anonymous tip line for anyone who wants to report possible violations is: 1-877-606-9183.