KUALA LUMPUR, Malaysia (AP) – Malaysia's High Court acquitted opposition leader Anwar Ibrahim of sodomizing a former aide, citing unreliable DNA evidence in a verdict Monday that surprised supporters who feared he would be imprisoned to silence him.

Anwar has long maintained that Prime Minister Najib Razak's ruling coalition concocted the charge to damage his chances of leading the opposition to an election victory. Najib, who is expected to call for national elections sometime this year, denies plotting against Anwar.

The case rested mainly on testimony by Anwar's 26-year-old accuser, Saiful Bukhari Azlan, and semen samples found on Saiful's body that investigators said matched Anwar's DNA.

High Court Judge Mohamad Zabidin Diah said his decision was founded on concerns that the DNA evidence was tainted.

``The court at this stage could not with 100 percent certainty exclude the possibility that the (DNA) sample is not compromised,'' Mohamad Zabidin told the court. ``Therefore it is not safe to rely on the (DNA) sample. There is no evidence to corroborate'' the charge.

A crowd of Anwar's supporters shouted ``Allahu Akbar,'' or ``God is great'' after the judge finished reading the verdict. Members of Anwar's family burst into tears and hugged him.

``Thank God justice has prevailed,'' a jubilant Anwar told reporters. ``I have been vindicated. To be honest, I am a little surprised.''

Anwar, whom the opposition regards as its future prime minister if it wins federal power, had earlier said he was bracing for a conviction, which could result in a maximum of 20 years in prison.

The verdict is expected to have a major impact on general elections that most politicians believe will be held some time this year. Anwar is the opposition's most charismatic politician and is considered the figure who can best hold the three ideologically distinct parties in his alliance together.

Thousands of opposition supporters gathered outside the court Monday, chanting ``Long live the people.'' Some carried banners that read ``Free Anwar'' and ``Reject slander.''

A police helicopter flew over the court, while riot police backed by a truck mounted with a water cannon monitored the crowd amid concerns that a conviction might spark unrest in Malaysia's largest city.

Defense lawyers had insisted Saiful's testimony was riddled with inconsistencies and that the DNA evidence was mishandled and tainted.

Anwar, a former deputy prime minister and married father of six, was jailed in another sodomy case in 2000 when he was convicted of sodomizing his family's ex-driver. He denied the allegation, and Malaysia's top court released him in 2004 by overturning his conviction and nine-year sentence.

Anwar said Monday that ''justice had been served'' with his acquittal in a contentious sodomy trial and pledged to topple the government in the next elections. ''Thank God, justice has been served,'' Anwar told reporters after a Malaysian judge pronounced him not guilty after a nearly two-year trial that he has denounced as a government attempt to cripple his strengthening opposition.

''I feel vindicated, but we still have an agenda and a struggle. We now have to focus on the general elec-tions,'' he said.

In a posting on his Twitter feed shortly after the ruling, Anwar said: ''In the coming election, (the) voice of the people will be heard and this corrupt government will be toppled from its pedestals of power.''

Prime Minister Najib Razak, who heads the ruling coalition that has governed Malaysia since independence from Britain more than five decades ago, is due to call new polls by early next year.

The court verdict had been hotly anticipated for its potential electoral impact, with the opposition's charis-matic leader facing the prospect of jail. It is the second sodomy verdict in a dozen years for Anwar, a former deputy premier in the 1990s who was next in line to head the country's long-ruling government until a spectacular downfall.

He had been groomed to succeed former prime minister Mahathir Mohamad until a bitter row between them saw Anwar ousted in 1998, beaten and jailed on sodomy and graft charges widely seen as politically motivated.

Once the sodomy charge was overturned in 2004 and he was released, the affair threw Anwar into the opposition, which he led to unprecedented gains against his former ruling party in 2008 general elections. But new sodomy charges emerged shortly after those polls -- Anwar was accused of sodomising a former male aide -- sparking accusations they were concocted by the ruling United Malays National Organisation to stall the opposition revival. Sodomy is illegal in Muslim-majority Malaysia and punishable by 20 years in jail.