Apple has removed the "Activation Lock" tool that allows users to check the ownership status of their iPhone, iPod touch or iPad.

The tool allowed users to enter the serial number or IMEI of iOS devices to find out if 'Activation Lock' was active, helping consumers who were interested in purchasing used devices avoid stolen ones.

Last year, Hemanth Joseph, a Kerala-based security researcher, has identified a bug running in iOS 10.1 version of Apple's operating system that allowed him to bypass the 'Activation Lock' on an iPad.

Joseph bypassed activation lock in a locked iPad by discovering a weakness in the device setup process running iOS 10.1.

The bug discovered by Joseph was reportedly fixed in an iOS update later.