The company said in a statement that CyberLens and Integrity, both well-known ICS asset and identification tools, would be made available free.

The cost of the acquisition was not divulged. Dragos is headed by the well-known researcher Robert M. Lee, the chief executive, who is a former NSA hacker. Among its executive line-up is another well-known name, Sergio Caltagirone, who functions as the vice-president of Threat Intelligence.

Integrity was originally developed under the name Sophia at the Idaho National Laboratory in 2012 and NexDefense, which was jointly founded by Michael Assante and Derek Harp, had been given the rights to commercialise and develop the tool.

CyberLens was developed by Lee, Justin Cavinee and Jon Lavender in their spare time when they were employed by the Department of Defence. The trio set up Dragos Security to continue the development of the tool.

In 2016, Dragos Inc was formed and a platform created to cater to those who needed security audits of industrial controls systems.

In its statement, Dragos said: "The ICS industry, as a whole, has matured substantially since Sophia was developed at INL and three young government employees built the assessment tool CyberLens. Those seeking a robust security strategy for their ICS will need more than these tools.

"The realisation of far more advanced and robust ICS asset identification capabilities with deep packet inspection, as well as the more difficult ICS-specific threat detection and response capabilities, exists within the Dragos Platform.

"However, Integrity and CyberLens represent a base-level capability that we are proud to now offer free to the community. It is our hope that this acquisition and product release pays homage to all the wonderful community members who worked on Sophia/Integrity over the years and provides a significant step forward for the members of the community just beginning their ICS cyber security journeys. It’s a long journey, but it is a worthy one to safeguard civilisation."