Testwell Laboratories and Stallone Testing Laboratories are accused of falsifying some results and not performing other tests.
New Jersey's Community Affairs Department alerted municipal code officials to examine "very large buildings" that have had concrete inspections since 2006.
Testwell had "limited involvement" in the Meadowlands football stadium that will open next year. Spokeswoman Alice McGillion says inspections found no problems.
Information from: The Record of Bergen County, http://www.northjersey.com