The Washington Post has unveiled four new slides, which give additional details of US surveillance programme, Prism.

According to the Washington Post, the government has installed equipment at each company to access the data.

The search request, dubbed a tasking, can be sent to multiple sources including to a private company and to an NSA access point which will tap into the Internet’s main gateway switches.

A tasking for Microsoft, Apple, Yahoo, Google, and other providers will be routed to equipment installed at each company.

The newspaper reported that the equipment will pass the NSA request to a private firm’s system and depending on the company, a tasking may return e-mails, attachments, address books, calendars, files stored in the cloud, text or audio or video chats and ‘metadata’ that identify the locations, devices used and other information about a target.

The report also reveals that analysts can conduct live surveillance using Prism and if a target turns out to be an American or a person located in the US, the NSA calls the collection inadvertent and destroys the results.

Last week, a bipartisan group of 26 US senators urged the director of National Intelligence, James Clapper, to reveal more information on the government’s surveillance programmes.