Andy Murray insists the revelation Andre Agassi took drugs during his career has not tarnished his opinion of his boyhood hero.

The former Wimbledon champion admitted in his autobiography he failed a test for crystal meth in 1997 and then lied about it to avoid a ban.

British number one Murray, who grew up idolising Agassi, revealed his surprise at the news but offered his support to the American.

"I don't think any of the players expected it but you've just got to move on," the 22-year-old said. "I loved Andre, met him numerous times. He was unbelievably nice to me. I practised with him quite a lot.

"I guess it's something he has to deal with him himself. He's entitled to say whatever he wants and I wish him the best.

"I judge him as a tennis player; he was great, one of the best of all time. No one wants drugs in sport but everyone makes mistakes."

The ATP have come under fire following Agassi's admission but Murray, who has complained the current drug-testing system is too intrusive, is confident tennis does not have a problem.

"I didn't play in those times so I don't know what it was like," he continued. "There are even cases now where guys get off, with failed tests and contaminations - mistakes, like with the (Richard) Gasquet case (where the Frenchman's ban for testing positive for cocaine this season was overturned).

"Sometimes things like that happen. People get away with it sometimes but I don't think drugs in tennis is a big problem like it is in other sports."

Murray returns to action at the Valencia Open this week after six weeks out with a left wrist injury, which he aggravated in Great Britain's Davis Cup defeat by Poland in September.

The Scot, who dropped to world number four after withdrawing from tournaments in Japan and China, is the top seed for the event and faces wild card Daniel Gimeno-Traver in the first round.

This will be the first ATP Tour meeting between Murray and the 24-year-old Spaniard, who hails from Valencia and is ranked 77th in the world.