An emotional Perera told reporters he had suffered "tremendous mental stress" after testing positive for a banned anabolic steroid in Qatar last year but insisted he always knew he would be eventually cleared.
"I had not done anything wrong, but I went through tremendous mental stress," Perera said at a press conference staged by Sri Lanka's board.
"I want to start practising and get back to international cricket at the earliest."
"I thank my fans and the board who stood by me during this trying period. I knew I would be cleared. I am relieved all this is over and I want to get back into form."
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While Perera was suspended during Sri Lanka's tour of New Zealand last December, his positive result came from out-of-competition testing at a laboratory in Qatar accredited by the world anti-doping authority (WADA).
"We regret what Mr. Perera has had to endure, and would like to commend him for the manner in which he has conducted himself throughout this period," ICC chief executive David Richardson said in a statement.
"We wish to make it clear that there is no evidence that Mr. Perera has ever used performance-enhancing substances and we wish him well in his future cricketing endeavours."
Sri Lankan board president Thilanga Sumathipala said his organisation had managed to get Perera's test results overturned after hiring a British law firm which advised them to commission independent scientific tests.
"He has been exonerated without a hearing, but based on the scientific evidence we provided," Sumathipala said adding that the board expected the ICC to reimburse the USD 100,000 costs of the tests and legal advice.
The ICC said it was seeking an urgent explanation from WADA and the Qatar laboratory that tested Perera's sample.
However, the Doping Analysis Laboratory insisted there was nothing wrong with their results and blamed a problem with "interpretation".
"It's crystal clear there's no problem. It's nothing to do with the laboratory, it's to do with the interpretation, the procedure," lab chief Costas Georgakopoulos told AFP in Doha.
However a Sri Lankan board official, speaking on condition of anonymity, said that Perera could be called up to join the team for a series of one-day internationals that will be played after the Tests.