A local doctor is concerned that Manitoba labs are putting patients in danger and the province is now conducting an external review into the matter.

Pediatric pathologist Dr. David Grynspan says he's noticed problems at provincial labs for the past two years.

Last month, he submitted a 20-page report to the province which outlined concerns about heavy workloads, lack of accountability and some senior managers over-billing for work. Grynspan says those factors compromise patient safety.

He says staffing levels may be to blame. Currently there are eight vacancies in the pathology department out of 46 positions. Grynspan says his report outlines one case where a patient's samples were misdiagnosed.

The province says it conducted an internal review of Grynspan's claims.

"It was shown at that time that the facts did not match the allegations and no patient harm was done," says Theresa Oswald, Manitoba's health minister.

The province still plans to carry out an external review of the report.

Tory health critic Myrna Driedger says the province's external review led by Winnipeg doctor Sharon McDonald won't be objective.

"I think we need a totally independent external review and an auditor on that committee to look into these allegations," says Driedger.

Other health officials say the external review led by McDonald will be fair.

"She is known for her objectivity," says Arlene Wilgosh, the board chair for Diagnostic Services Manitoba, the group which oversees the province's public labs. Wilgosh says McDonald is bringing in a pathologist from outside the province, along with an independent labour lawyer to help in the external review.

Grynspan says he doesn't agree with the review process and would like to see a completely external auditor do a thorough investigation of the pathology department.

The province, meanwhile, says the findings of McDonald's investigation may be made public if it turns out patient safety was in danger.

- with a report from CTV's Karen Rocznik