Two-time Olympic 200m champion Veronica Campbell-Brown says she has been cleared to race again by the Court of Arbitration for Sport (Cas).
The 31-year-old Jamaican has not competed since she tested positive for a banned diuretic last May.
Campbell-Brown said in a statement: "The final court available to us as athletes have spoken and humbly I say they have confirmed my innocence."
She added the past few months have brought "much pain and suffering".
Campbell-Brown was provisionally suspended by the Jamaica Athletics Administrative Association after failing a test at the Jamaica Invitation meeting on 4 May.
In October, a Jamaican disciplinary committee review deemed a reprimand was sufficient punishment because the banned substance was not used for performance enhancement.
However, Campbell-Brown, who has won seven Olympic medals, had to wait for the IAAF's verdict before she could compete again. It appears the body that governs world athletics decided to hand the case to Cas.
Campbell-Brown added: "Yes, I lost out on the opportunity to compete for most of 2013 and the chance to defend my World 200m title. However, I press on.
"Dr Martin Luther King Jr spoke of the redemptive quality of unearned suffering and I must say I am redeemed."
She also thanks the IAAF for "expeditiously handing my case to Cas".
Campbell-Brown could return to competition at next month's World Indoor Championships in Poland, with the Commonwealth Games in Glasgow in July also an option.
Monday's news is a boost for Jamaican athletics, which has been under scrutiny following a series of failed tests.
Last year, Asafa Powell and Sherone Simpson tested positive for banned substances and missed the World Championships in Moscow.
In 2009, Jamaican sprinter Yohan Blake and three other islanders received reduced suspensions of three months after testing positive for a banned stimulant.