As many as 450 Ozaukee County employees social security and tax information is at risk after fraudulent activity occurred on a employee website, according to the Ozaukee County Administrator. 

Thomas Meaux, county administrator, said that on February 14-15 the county's third party vendor started seeing activity on the employee portal. This portal is a site run by this company that has employee hours worked, personal information and tax information.

The county knows there are 20 employees that had fraudulent tax returns filed.

There are as many as 200 that could be compromised and as many as 450 employees are at risk. 

The county has shut down the employee portal as of last Thursday.

The Ozaukee County Sheriff and the Internal Revenue Service is investigating.  

They have no specific source as to where this was coming from, Meaux said the IP addresses that were accessing the site were from all over the country.

The county is assisting employees with identity theft protection and fraud protection