ORLANDO, Fla. -- Channel 9 has uncovered more fraudulent documents in the scandal surrounding the city permitting office and the Grande Condominiums in downtown Orlando.

GET WFTV NEWS HEADLINES BY EMAIL 9 a.m. Headlines Noon Headlines 4 p.m. Headlines News of the Strange Breaking News Alerts

Eyewitness News has repeatedly asked the city to prove that underground fire sprinkler mains were properly installed and inspected.

The city has provided Channel 9 with several versions of an inspection certificate that was questioned more than a week ago. There are three versions of the same document, and two out of the three appear to be fake. Now the city faces a serious investigation by the State Fire Marshal.

A document called an NFPA 24 certifies that underground fire sprinkler lines are properly installed and tested, but Channel 9 found that someone has created fraudulent certificates using real documents.

The city provided Channel 9 with a document from CDS Sitework and Trucking, a company that's not licensed to do fire protection work. Channel 9 compared their NFPA 24 certification to another company's certification, Wayne Automatic Sprinklers.

The two documents are identical, except for a few alterations. The Wayne Automatic Sprinklers signature was erased and replaced by another name. The top of the document shows that someone altered the permit number, but at the bottom of both forms the name of Wayne Automatic Sprinklers appears. It seems one document was used to forge another.

A manager at CDS Sitework and Trucking did not want to talk about the forged papers Monday when Channel 9 tried to get answers.

Tuesday, the city stood behind the fire suppression system at The Grande.

"We feel comfortable that everything is working correctly and that there is no public safety issue. There's no one at risk," said Tanja Gerhartz, director of Economic Development.

But the city's economic development director wouldn't answer tough questions about the doctored documents.

"Are you not concerned that there are doctored documents in the file?" WFTV reporter Steve Barrett asked Gerhartz. "You can ignore this document all you want, but isn't it to the core of what you do in the permit office?"

At that point, the interview was over. The economic development director walked out.

Residents of The Grande Condominiums are now considering their own legal action. The owners of the $200,000-plus condos are concerned about their investments and their safety.

"I hope that it was just a misunderstanding, or at least that it will be corrected," said condo-owner Alexis Pepaj.

The State Fire Marshal's office has already re-opened its investigation into the permitting of the property. Tuesday, the office requested copies of the nearly identical documents. Channel 9 also sent copies to the Orlando Police criminal investigation division.