Microsoft has terminated the Israeli military's access to technology it used to operate a powerful surveillance system that collected millions of Palestinian civilian phone calls made each day in Gaza and the West Bank, the Guardian can reveal.

Microsoft told Israeli officials late last week that Unit 8200, the military's elite spy agency, had violated the company's terms of service by storing the vast trove of surveillance data in its Azure cloud platform, sources familiar with the situation said.

The decision to cut off Unit 8200's ability to use some of its technology results directly from an investigation published by the Guardian last month. It revealed how Azure was being used to store and process the trove of Palestinian communications in a mass surveillance programme.