Ronnie O'Sullivan warned for gesture at World Championship

Ronnie O'Sullivan is warned by referee Michaela Tabb for what she believes was an improper gesture during his World Championship semi-final against Judd Trump.

The Rocket finished the session 14-10 up in the best-of-33 contest.

O'Sullivan is no stranger to controversy and created headlines at the year's championship after saying he only returned to snooker because he needed the money.