Mercedes-Benz USA is currently being investigated by U.S. safety regulators who suspect that the automaker is taking too long not just to send out safety recall notices to customers, but to also inform the federal government about them.

According to the NHTSA, there have been numerous instances in which Mercedes owners of recalled models weren’t notified within the federally mandated 60-day window, reports Automotive News.

It would appear that Mercedes “omitted critical information about the problem for which a recall decision was made, or details about its recall plans,” said Stephen Ridella, director of NHTSA’s Office of Defects Investigation Enforcement in a letter to the company, while also questioning the automaker’s “process and cadence” for making recall decisions and notifying authorities about them.

The letter also claimed that Mercedes often failed to meet the performance requirements needed to support the NHTSA’s tool to look-up vehicle identification numbers, and that the federal agency is now opening an audit query to investigate matters such as owners “not being able to obtain critical information about open safety recalls on their vehicles.”

Meanwhile, Mercedes sent out an e-mail statement saying that it makes “every effort to ensure our recall campaigns and customer notifications are executed in a timely manner. We will work closely with NHTSA on this audit query to address its concerns.”