DENVER -- A well-known Denver doctor received a ballot for Tuesday's election despite the fact that he died in 2003, a CALL7 investigation found.

Dr. Peter A. Vargas, who worked at Rose Medical Center and with Rocky Mountain Planned Parenthood, died in August of 2003, but the current resident of his home received a ballot last month with the doctor's name on it.

CALL7 Investigators returned the ballot Monday, but used hidden cameras to capture election officials' reaction to the obviously erroneous ballot.

"We know this is serious stuff. We take it seriously. We thank you as a citizen for bringing this in," an elections manager said.

"I could have voted this?" the 7NEWS producer asked.

"Yes, you could have," the election worker said, adding that it would have been a crime to sign the affidavit required to make the ballot count.

The Denver Elections Division is supposed to get an updated list of deaths from the state Department of Public Health and Environment, but Denver Clerk and Recorder Stephanie O'Malley said Vargas was not on the list.

"If this person who is well known in Denver died six years ago and the state health department doesn't have a record it gave you, then how many others?" CALL7 Investigator John Ferrugia asked.

"There could be a lot," O'Malley said. "There could be hundreds of those, thousands."

When asked if there needs to be an audit or investigation of why the lists are not accurate, O'Malley said, "I think it's a fair question back to the Colorado Department of Environmental Health as to why we hadn't received that notification. I think that's a fair question."

O'Malley also noted that there is another important safeguard in the Denver voting system: signature verification.

The signature of each person turning in a ballot, whether they mailed it in or voted in person at the polls, is checked against a signature card on file with the county.

So, if a person tries to vote a ballot not his own, it is often questioned by election workers who visually check each signature.