Microsoft has cut off some services to a unit of Israel's Ministry of Defence after an investigation found its technology had been used to conduct mass surveillance on people in Gaza.

Brad Smith, president of the company, said using the firm's technology to conduct mass surveillance on civilians was a violation of its standard terms of service.

Mr Smith said the decision, which was prompted by an investigation published by The Guardian, would not affect other work the company does with Israel.

Microsoft's work with the Israeli government has been a controversial issue, including within the company, prompting protests by employees.

"I know many of you care about this topic," Mr Smith wrote in a message to staff that was published by the company on Thursday.

He emphasised that the review was ongoing: "I'll share more information in the coming days and weeks, when it's appropriate to do so."

Last month's investigation by the Guardian, which collaborated with Israeli-Palestinian publication +972 Magazine and Hebrew-language outlet Local Call, found that a unit of the Israeli defence ministry used the expansive storage capacity of Microsoft's cloud service, Azure, to create a giant trove of calls made by ordinary Palestinians that it had intercepted.

The ability to collect, play back and analyse communications with such breadth helped to shape military operations in Gaza and the West Bank, according to their investigation.

Microsoft, which has responded to protests from staff over its work for Israel by firing some employees, said it launched its own review in response to the article.

The company said it did not access the content of its customers as part of that review but found other evidence to support elements of the article, including consumption of storage capacity in the Netherlands and use of AI services.

It subsequently informed the Israeli Ministry of Defence that it would "cease and disable" certain "subscriptions and their services, including their use of specific cloud storage and AI services and technologies", according to Mr Smith.

"We have reviewed this decision with IMOD and the steps we are taking to ensure compliance with our terms of service, focused on ensuring our services are not used for mass surveillance of civilians," Mr Smith wrote, saying the firm's review had been guided by its commitment to privacy.

The Guardian reported that the unit in question planned to transfer its data to a cloud platform sold by Amazon. Amazon did not respond to a request for comment.

Earlier this year, a United Nations expert called on dozens of multinational companies to stop doing business with Israel, warning them they risked being complicit in war crimes in Gaza and the occupied West Bank.

Microsoft was among those named in the report from Francesca Albanese, which was presented to the UN human rights council.

It also names firms such as Amazon and Alphabet, which like Microsoft, have faced internal pressure on the issue from some staff.