No charges had been levelled against the 60-year-old former deputy prime minister, who was sacked and jailed a decade ago in a similar case which was quashed in 2004, Anwar's lawyers told media-persons.
Anwar was arrested near his home on Wednesday an hour before a deadline set by the police for him to appear voluntarily for questioning in connection with a complaint filed by a former aide on June 28 accusing him of sodomy.
The People's Justice Party chief was driven off from the back exit of the police headquarters accompanied by his wife and daughters as a horde of journalists waited outside.
The police recorded Anwar's statement in connection with a sodomy allegation, his lawyer Sankara Nair said.
Nair said Anwar, who was once a part of the powerful ruling coalition and led an opposition upsurge in the March polls, had been asked to report to the city police on August 18.
His lawyers, however, said Anwar had refused to give a DNA sample as he feared that it would be used to fabricate evidence.