Refusing to compare Dale Steyn with Australian speedster Mitchell Johnson, Pakistan pace legend Waqar Younis on Saturday hailed the South African as the world's best fast bowler and one of the greats seen in the last 20-30 years.

"I regard him as one of the best in the world for the last 20-30 years. I don't think even in South Africa, they have produced anybody like Steyn in the past. For me Steyn is definitely the number one bowler," said Waqar on the sidelines of a programme here.

Talking about Johnson, who powered Australia to whitewash their arch-rivals England in the Ashes, Waqar said the lanky Aussie has just found his rhythm while Steyn was a proven performer since the last decade.

"Both are fine bowlers, but you cannot compare them. Johnson has just found his rhythm in the last few months. But Steyn has been outstanding for the last ten years. I think Steyn is far better," said Waqar.

Waqar and Sri Lankan spin ace Muttiah Muralitharan have been roped in by the Cricket Association of Bengal to train upcoming bowlers.

While Steyn with 362 Test wickets is far ahead, Johnson ended up with 22 wickets - ten more than Steyn - from three matches in the recently concluded series against the Proteas.