Sir Ian Botham has spoken of his shock and sadness at the death of "big brother" Bob Willis.

The former England captain died of cancer on Wednesday at the age of 70, prompting a flood of tributes from across the cricketing world.

Botham played with Willis for England and continued to work alongside him in broadcasting once both had retired.

The 64-year-old Botham told Sky News: "He was a guy that, whenever I had problems in the cricketing world or in (my) personal life, he was always there to help me.

"He was like a big brother and we had some amazing times together around the world. There are certain friendships you have in your life but very few as close as it was with Bob.

"An amazing guy, great cricketer, very underestimated by a lot of people for many years. He was the best quick bowler I played with representing England because he was quick. He was a unique bowler, because you would never teach anyone to run up and bowl like that.

"I knew that he was very, very ill. I saw him last Thursday, went down and sat with him for a while, but when it actually happens it's a major shock still. You can't really be prepared for losing such a close, close friend."

Former England captain Nasser Hussain, another colleague at Sky Sports, said Willis' death leaves a hole "that's impossible to fill".

Writing on skysports.com, Hussain said: "Genuine, humorous and down-to-earth – Bob Willis loved life and leaves a hole in the cricketing world that's impossible to fill.

"Bob was passionate about the game and if he hadn't made such a superb broadcaster, he would have been a fabulous director of England cricket.

"He understood how lucky he was to be involved in cricket and was such a pleasant bloke to spend time with, treating people the same across the board."

Willis remains England's fourth-highest wicket-taker of all time, taking 325 scalps in 90 Tests, and his most famous moment as a player came in the remarkable third Ashes Test at Headingley in 1981.

Botham's innings of 149 had helped set Australia a target of just 130 to win when Willis produced the performance of his life, taking eight for 43 to secure an improbable 18-run victory.

A number of current England players paid tribute to Willis.

Captain Joe Root wrote:  "A true England great. Fantastic player, pundit and a lovely man with a great sense of humour. Love to all his close family and friends as well."

James Anderson, one of the three players to take more wickets than Willis for England, wrote: "Incredibly sad to hear the news about Bob Willis. He was a true great, generous in sharing his knowledge about the game and a lovely man."

Willis' family said in a statement: "We are heartbroken to lose our beloved Bob, who was an incredible husband, father, brother and grandfather. He made a huge impact on everybody he knew and we will miss him terribly.

"Bob is survived by his wife Lauren, daughter Katie, brother David and sister Ann.

"The Willis family has asked for privacy at this time to mourn the passing of a wonderful man and requests that in lieu of flowers, donations should be made to Prostate Cancer UK."