Transport for London (TfL) has doubled tablet usage for staff at work over the last two years, according to a Freedom of Information request.
The underground train operator handed a total 3,500 tablets to staff last year, almost double the 1,766 issued in 2012.
It comes after TfL revealed BYOD adoption had grown 500 per cent in the three years since 2010, counting 573 personal devices on the corporate network in 2013.
However, the company behind the FoI, app security expert Veracode, pointed out that the number of tablets in use raises a number of security issues.
These potential problems the risk of exposing sensitive data related to phones and tablets used at work.
Chris Wysopal, co-founder and CTO of Veracode, said: "Equipping workers with the latest mobile devices will help improve commuter experience and streamline day-to-day administrative activity across London's transport infrastructure.
"While TfL is leading the way in embracing the latest technologies, it should also ensure that rigorous security measures are put in place to reduce risk from mobile malware and unsafe applications."
The number of mobile phones given to staff by TfL has also increased by around a third over five years, and laptops by 14 per cent.
Since 2010, the total number of mobile devices handed out to employees has risen 48 per cent to 15,935.
And Wysopal warned: "Cybercriminals relentlessly target mobile applications to steal sensitive data and spy on mobile users.
"As a result, it is now becoming a best practice for organisations to implement mobile device management (MDM) systems powered by continuously-updated security intelligence about unsafe and malicious mobile apps to enforce security and privacy policies on their employee's devices in order to keep cyberattackers out."
The news comes the same month as TfL released traffic details for its new website, saying tablet users made 23 million visits to the site in the past year.
Another 120 million visits came from mobile and 107 million from desktops.
