8 November 2013 Last updated at 19:40 GMT

Andy Murray has no sympathy for Viktor Troicki and Marin Cilic

Andy Murray says a lack of professionalism led to failed drugs tests for Viktor Troicki and Marin Cilic.

Opinion has been divided on Troicki's one-year ban for failing to undergo a blood test, with his compatriot Novak Djokovic calling the punishment a "total injustice".

Cilic served a four-month ban for ingesting a prohibited substance, an offence for which Murray says there is "no excuse".