A business premises suspected of making 200 million illegal calls has been searched by the Information Commissioner’s Office (ICO).
Some calls may have put lives at risk as they were made to Network Rail’s control centre near Fort William.
As a result drivers and pedestrians were unable to check if it was safe to cross the rails at unmanned crossings.
The raid in Clydebank, West Dunbartonshire, followed public complaints about automated calls
Typically they were recorded messages promoting boiler and window replacement schemes.
The ICO said they often referred to non-existent Scottish or UK government initiatives.
Ken Macdonald, head of ICO Scotland, said: “These calls have caused millions of people disruption, annoyance and distress, but not only this, those made to a control centre charged with public safety may have endangered lives.
“Companies behind nuisance calls should know that people are sick of them, and when people complain to us, we will act.”
The regulator said it would not name the firm while the investigation is ongoing.
The 200 million plus calls the firm is suspected of making is one of the highest volumes the ICO has ever executed a search warrant in relation to.
To date, the highest number of calls to result in an ICO fine is 146 million.
Computer equipment and documents were seized for analysis during the search, and will now be used to inform the ICO’s investigation.
The regulator has powers to issue fines of up to £500,000 for breaches of the Privacy and Electronic Communications Regulations 2003, which cover the way organisations make automated direct marketing telephone calls.