The shock announcement comes as he admitted that he sent explicit messages to a former female Cricket Tasmania employee in 2017.
This is everything you need to know.
Why is Tim Paine stepping down as the Australian cricket captain?
Paine has announced that he will be stepping down as the Australian Test cricket captain “effective immediately” over a sexting exchange with a former colleague which took place in 2017.
While Paine did not address the nature of the text messages, Cricket Australia’s news website referred to it as “revelations of a sexting incident involving a former Cricket Tasmania employee in 2017”.
Cricket Tasmania chairman Andrew Gaggin said that at the time of the incident, no complaint was made.
It was only when the female employee had been charged with theft that she raised the allegations against Paine in mid 2018, with the messages having been exchanged in November 2017.
Gaggin said: “As soon as Cricket Tasmania was made aware, it undertook an investigation that determined the interaction was consensual, private, occurred on the one occasion only, was between mature adults and was not repeated.
“Cricket Tasmania clearly does not condone this type of behaviour and addressed the matter directly with Tim Paine. However, because of the consensual nature of the actions it was determined that no further action was required or appropriate.”
What has Tim Paine said?
While speaking to reporters in Hobart, Paine said while the decision to step down has been “incredibly difficult” it is ultimately the correct one for him, his family and for cricket.
He said: “As a background on my decision, nearly four years ago I was involved in a text exchange with a then colleague.
“At the time, the exchange was the subject of a thorough CA (Cricket Australia) Integrity Unit investigation, throughout which I fully participated in and openly participated in.
“That investigation and a Cricket Tasmania HR investigation at the same time found that there had been no breach of the Cricket Australia code of conduct.
“Although exonerated, I deeply regretted this incident at the time and still do today.”
He added that he thought “this incident was behind us” however he had recently become aware that the private text messages were going to be made public.
Paine said: “On reflection, my actions in 2017 do not meet the standard of an Australian cricket captain or the wider community.
“I am deeply sorry for the hurt and pain that I have caused to my wife, my family and to the other party.
“I am sorry for any damage that this does to the reputation of our sport and I believe that it is the right decision for me to stand down as captain effective immediately.
“I do not want this to become an unwelcome disruption to the team ahead of what is a huge Ashes series,” added Paine, who captained Australia in 23 Tests for 11 wins, eight losses and four draws.
“I’ve been blessed with a wonderful, loving and supportive family, and it breaks my heart to know how much I’ve let them down. They have always stood by me, been my most loyal fans, and I’m indebted to them for their support.
“I have loved my role as captain of the Australia cricket team and it has been the greatest privilege of my sporting life to lead the Australian men’s Test team.”
What has Cricket Australia said?
Cricket Australia Chair Richard Freudenstein said the Board had accepted Paine’s resignation.
He said: “Tim felt it was in the best interests of his family and Australian cricket to take this decision to step down as captain.
“The Board has accepted Tim’s resignation and will now work through a process with the National Selection Panel of identifying and appointing a new captain.
"While the Board acknowledges an investigation cleared Tim of any breach of the code of conduct regarding this matter some years ago, we respect his decision.
"Despite the mistake he made, Tim has been an exceptional leader since his appointment and the Board thanks him for his distinguished service.
"Tim will continue to be available for selection in the Test team through the Ashes summer."
Who is Tim Paine’s wife?
Paine’s wife is Bonnie Paine, and the two of them married in 2016. The couple have two children together - daughter Milla and son Charlie.
According to her Instagram account, she is a registered nurse and Studio HQ ambassador.
Who will be the next captain?
Paine’s resignation as captain comes just three weeks before The Ashes, which will begin next month on 8 December as Australia hosts England in Brisbane.
He had been elevated to the position of Australia’s 46th Test captain in 2018 somewhat unexpectedly after former captain Steve Smith admitted to his involvement in the infamous ball-tampering scandal in South Africa.
Paceman Pat Cummins is the current vice-captain and most likely choice to become the team’s new leader.
While Cummins is seemingly first in line to take over from Paine, Australia has typically been extremely reluctant to have a bowling captain. Their last was leg-spinning all-rounder Richie Benaud, in the early 1960s.
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