"Then she tried to snatch the thermometer out of my hands," said Holland, who claimed she then got into a scuffle in front of customers and co-workers.
A Burger King New Zealand spokesman told the Herald that "at first glance there are a number of inaccuracies" in Unite's statement.
"We are aware of the situation and have a meeting tomorrow morning with the staff members involved, including Abby, to ensure we have all the facts."
West Auckland police have been informed.
A police spokeswoman said enquiries were "ongoing" and no further details were available.
In 2012 19-year-old worker Lynette Fray claimed her manager attacked her at the Lincoln Rd Burger King and had to be pulled off by four co-workers.
Unite said it has raised concerns about the inadequate air conditioning at the Lincoln Rd restaurant on several occasions, as well as the company's failure to provide employees with needed rest breaks for health and safety reasons.
"Workers and the union have been met with repeated delays, excuses and have been provided with incorrect information since reporting the widespread non-provision of breaks at Lincoln Road Burger King last year," Unite said.
Unite is asking Burger King to provide CCTV footage of Sunday's alleged scuffle.