The Iniyan Challenge

It is usual for rook endgames to end in a draw. At least, they usually have a strong tendency to do so. Recently young grandmaster Iniyan visited our company and showed us a position from one of his games which should be won by White. But he needed to work very hard to do so. Even our endgame expert Dr. Karsten Müller, and a visiting super-GM colleague of Iniyan had great difficulty finding the win. Can you help find the convincing proof?