The Kuala Lumpur High Court determined that DNA evidence offered by prosecutors could be unreliable and said it would not convict Anwar Ibrahim (pictured) without corroborative evidence.
Sodomy is a crime in majority-Muslim Malaysia; Ibrahim had been facing up to 20 years in jail.
The opposition politician claimed the case was a political conspiracy by Prime Minister Najib Razak’s administration.
He had been prosecuted and convicted on charges of sodomy and abuse of power previously, but the High Court overturned the conviction in 2004.
After he led the opposition to deprive the governing party of its two-thirds majority in parliament in 2008, Ibrahim was once again charged with sodomy – this time with a former political aide.
Ibrahim dismissed the allegation as a “blatant and vicious lie”.
Acquitting Ibrahim this week, Judge Mohamad Zabidin Diah told the courtroom: “This court at this stage could not, with 100 per cent certainty, exclude the possibility that the sample is not compromised.
“Therefore, it is not safe to rely on the DNA sample.”
The Asia division of Human Rights Watch welcomed the court’s decision, insisting that the charge “should have never been brought in the first place”.
Deputy director of the Asia division Phil Robertson said: “Hopefully this verdict sends a message to the government to put this matter to rest.”
After Ibrahim was acquitted, supporters cheered “Long live the people” and “Reform.”