DENVER (CBS4)- The Colorado Department of Health is re-testing more than 1,700 blood alcohol samples from drunk driving cases.

An employee misreported several test results and now all of his testing has come into question.

“On Friday March 9, 2012 it was brought to my attention that several blood samples analyzed by Mr. Fox were reported outside the appropriate reporting range,” read attorney Steve Katzman from an email from the Colorado Dept. of Health.

That email shows that 1,700 block alcohol samples must be re-tested. An independent test showed that an employee reported some blood alcohol levels incorrectly.

“We determined when we first heard of this issue from the deputy DA we realized the sample that he brought to our attention and found that it was in fact higher than the result we got here,” said Colorado Department of Public Health spokesman David Butcher.

The name of the employee cannot be released but an email from the state toxicology lab supervisor obtained by CBS4 lists him as Mitchell Fox-Rivera.

Rivera ran several blood alcohol tests for some of Steve Katzman’s clients.

“It means that the reliability of the samples and the results that we’ve gotten from the Department of Health are called into question,” said Katzman.

Scientists and lab technicians will be working overtime on weekends over the next month to catch up on the re-testing. All of the re-testing should be completed by the end of next month.

So far 250 blood samples out of the 1,700 have been re-tested. Only 10 were reported incorrectly. Mitchell has since been fired.

“We could not verify the quality of the work he was doing in the lab,” said Butcher.

The State Health Department said there is no way to prove if the misreporting was intentional or accidental.