Tennis player Andre Agassi has revealed he took crystal meths in the late 90s.

Agassi, an eight-time grand slam winner, used the drug with his former assistant 'Slim'.

In his new autobiography, entitled Open, Agassi also revealed that he tested positive for the drug in 1997 but escaped a ban by claiming his use had been accidental.

"There is a moment of regret, followed by vast sadness," Agassi wrote about taking the drug.

"Slim dumps a small pile of powder on the coffee table. He cuts it, snorts it. He cuts it again. I snort some.

"Then comes a tidal wave of euphoria that sweeps away every negative thought in my head. I've never felt so alive, so hopeful - and I've never felt such energy."

The exert, which has been serialised by The Times newspaper, has sent shock waves through the tennis world.

Widely regarded as one of the game's greatest players, Agassi was well-known for his flamboyant play on the court.

The 39-year-old, who retired from the game in 2006 to spend time with wife Steffi Graf, admitted in another exert that he had thought hard about revealing his drug use.

But he added: "I was actually excited about telling the world the whole story."

The Association of Tennis Professionals (ATP), which governs the game, is reported to be considering a response to the claims in the book.