In the hours after his name became known, the entire world was searching for the NSA whistleblower, and it became vital that his whereabouts in Hong Kong remained secret. In an extract from a new book, No Place to Hide, Glenn Greenwald recalls the dramatic events surrounding the moment Snowden revealed himself in June 2013

On Thursday 6 June 2013, our fifth day in Hong Kong, I went to Edward Snowden's hotel room and he immediately said he had news that was "a bit alarming". An internet-connected security device at the home he shared with his longtime girlfriend in Hawaii had detected that two people from the NSA – a human-resources person and an NSA "police officer" – had come to their house searching for him.

Snowden was almost certain this meant that the NSA had identified him as the likely source of the leaks, but I was sceptical. "If they thought you did this, they'd send hordes of FBI agents with a search warrant and probably Swat teams, not a single NSA officer and a human-resources person." I figured this was just an automatic and routine inquiry, triggered when an NSA employee goes absent for a few weeks without explanation. But Snowden suggested that perhaps they were being purposely low-key to avoid drawing media attention or setting off an effort to suppress evidence.