The US National Secutiry Agency (NSA) has knew about the Heartbleed bug for at least two years before it was revealed, according to Bloomberg.
One person 'familiar with the matter' told the news agency that the NSA preferred to keep the bug secret in order to harvest the private data the flaw exposed.
More top news
A keeper killed by a tiger at a zoo in Cambridgeshire has been named in reports and described as the "shining light" of her workplace.
The two women charged with murdering the half-brother of North Korean dictator Kim Jong-un have appeared in court in Malaysia.
More than one million families will benefit from Labour's plan to overhaul "patchy" childcare provision, the party has said.