A Harris County election official told the Senate that 24 registered voters cast ballots after their date of death, some in multiple elections.
"Several of these voters voted early and in person," said Ed Johnson, assistant director of voter registration in the Harris County tax office.
"There is voter fraud in Harris County," Johnson said. "I can't tell you how extensive it is."
Johnson said the Web site Texas Watchdog gave his office a list of 4,000 names of possible dead voters created by comparing the registration list against Social Security documents. He said they are reviewing the list.
But Johnson said Texas Watchdog gave the list to a Houston television station that found two people on the list had voted in the 2008 primary.