A young British computer expert hailed a hero for helping to shut down the crippling cyber attack said he was just "doing my bit" to stop the hackers.

Marcus Hutchins, 22, discovered a so-called "kill switch" that slowed the effects of the WannaCry virus as it swept through computer systems around the world.

Large swathes of the NHS were paralysed by the cyber attack on Friday, which hit 200,000 victims in 150 countries around the world.

But Mr Hutchins, who works for Los Angeles-based Kryptos Logic but is from Ilfracombe in north Devon, spent the weekend fighting against the virus that meant computer systems were able to return to relative normality.

Speaking to the Associated Press, he said: "I've had people, sort of inundating me with messages thanking me, saying that I'm a hero.

"I mean I sort of just registered this domain for tracking. I didn't intend for it to like, sort of blow up and me to be all over the media.

"I was just sort of doing my job and I don't really think that I'm a hero at all."

How did he do it?

Mr Hutchins' major contribution to helping stop the crippling cyber attack has gained him world-wide attention.

"I've still been working across from my company Kryptos Logic, we've been trying to provide the sort of, the IP addresses to NCSC (National Cyber Security Centre), the FBI, so that victims can be notified," he said.

"We've been having queries from like CERTs (Computer Emergency Response Teams) around the world, obviously journalists are sort of inundating me with their queries.

"We're just pretty much business as usual except I have not had any sleep in three days.

"My name is out in the papers (and) my general location is, so I don't think I'm ever going back to being the malware tech that no one knew."