WASHINGTON, Aug 7, 2008 (AFP) - The United States on Thursday highlighted doubts raised over sodomy charges against Malaysian opposition leader Anwar Ibrahim, as a top Malaysian envoy was summoned to the State Department over the case.

"We take note of the many serious questions raised within Malaysia, including by the Malaysian Bar Council, concerning this case," a State Department official told AFP.

Anwar was released on bail Thursday after pleading not guilty to sodomy charges ahead of a by-election expected to return him to parliament this month.

The former deputy premier, jailed a decade ago on similar charges that were later overturned, has said the new allegations have been concocted by the government to prevent him from seizing power.

Human rights watchdogs also felt the charges were politically motivated, with the Malaysian Bar Council, a top lawyers group, raising a series of questions over the police investigation into the charges.

"We again urge Malaysian authorities to resolve the matter in a manner that builds confidence in the impartial rule of law and the proper functioning of democratic institutions in Malaysia," said the State Department official, speaking on condition of anonymity.

On Wednesday, Ilango Karuppannan, the charge d'affaires of the Malaysian embassy in Washington, was summoned to the State Department before charges were filed against Anwar in Kuala Lumpur, officials said.

The department confirmed that a meeting took place with the envoy over Anwar's case and other issues but did not provide details.

"We have regular exchanges with Malaysian diplomats in Washintgon on a number of subjects, including with the Malaysian charge (d'affaires) yesterday," the department official said.

"Anwar Ibrahim's case was one of the topics of conversation."

The US actions may further infuriate the Malaysian government.

Kuala Lumpur accused Washington of meddling in its internal affairs when US Secretary of State Condoleezza Rice last month raised concerns over the investigation into the claims against Anwar.

Anwar was accused of sodomising 23-year-old aide Mohamad Saiful Bukhari Azlan on June 26.

Sodomy, even between consenting adults, is illegal in this conservative and predominantly Muslim nation. It carries a penalty of 20 years imprisonment.