Dr. Brian Day was declared the winner last week by just one vote, but the group's CEO Allan Seckel says there was another vote that should have been counted.
That means day and Dr. Allan Ruddiman tied.
Seckel says a run-off vote will now be conducted between the two candidates between June 5 and 18.
Day founded the private Cambie clinic about two decades ago but came under fire in a 2012 audit for illegally charging patients for services.
He has since challenged the B.C. government in court, arguing that a Canada Health Act prohibition that prevents doctors from billing patients privately is a charter violation.