Nearly 6.5 million passwords belonging to users of the professional social networking site LinkedIn have been leaked online.
Users are being urged to change their login details over fears that the leak would compromise vast amounts of personal data, including contact information.
Experts have also advised users to change their login details elsewhere if they use the same password.
The information was reportedly posted as encrypted on a Russian hackers’ website and 300,000 are said to have been decrypted, with work ongoing.
LinkedIn director Vicente Silveira said: "We can confirm that some of the passwords that were compromised correspond to LinkedIn accounts.
"Members that have accounts associated with the compromised passwords will notice that their LinkedIn account password is no longer valid. These members will also receive an email from LinkedIn with instructions on how to reset their passwords.
"These affected members will receive a second email from our customer support team providing a bit more context on this situation and why they are being asked to change their passwords."
LinkedIn has more than 160 million users in 200 countries and nine million in the UK, including many in the travel industry.
It has already faced criticism after it was revealed that its mobile app was sending information from users’ phones back to the company in plain text.
* TravelMole Asia Pacific can confirm the when it opened an authentic-looking message from Linkedin today, it connected to a website selling Viagra.
