KUALA LUMPUR, Feb 29 (AFP) - Lawyers for Malaysia's Anwar Ibrahim told the appeal court Tuesday that a top policeman who gave crucial prosecution evidence in the sacked deputy premier's corruption trial was a liar.

On the second day of a bid to overturn Anwar's conviction last April for corruption and his six-year jail sentence, they attacked the credibility of Mohamad Said Awang, director of the police Special Branch in 1997.Lead counsel Raja Aziz Addruse told a three-member panel led by appeal court president Lamin Yunus that Mohamad Said's evidence was "highly questionable."

Mohamad Said testified in the trial that Anwar had directed him to obtain retractions from two people who accused him of sexual misconduct.Anwar, once heir apparent to Prime Minister Mahathir Mohamad, was convicted of four counts of corruption -- abusing his official powers to cover up the allegations of homosexual and heterosexual misconduct.

Azizan Abu Bakar, then-driver for Anwar's wife, and Ummi Hafilda Mohamad Ali, the sister of his former political secretary, had written to Mahathir in August 1997 making the claims.

Raja Aziz read parts of the trial record to show that Said was not a reliable witness and that there were inconsistencies in his answers.The lawyer referred to an answer Mohamad Said gave when asked by the defence whether he would lie in court if someone more senior than the deputy prime minister asked him to do so.

Mohamad Said had replied: "I may or (may) not lie."

Raja Aziz told the appeal court: "He was demolished in cross-examination right from the beginning."

Lamin asked the lawyer if he was trying to show that once a person had lied, he would always be lying.

"I don't know when he's lying but he is a liar," replied Raja Aziz.

He quoted more evidence from Mohamad Said and added: "There seems to be nothing definite from him. He seems to be very evasive."

Raja Aziz said Judge Augustine Paul lacked objectivity in evaluating evidence, noting that Paul had "based his conclusion (that Mohamad Said was a credible witness) on demeanour."

He said Paul's move to expunge evidence of alleged sexual misconduct, after prosecutors were allowed to amend the charges at the end of their case, had prevented the defence from challenging witnesses.

The amendments meant that the truth or falsity of the allegations need not be proved, only that Anwar had tried to cover them up.

"We were supposed to shut our minds as the judge did," Raja Aziz said. "(But) far from securing the ends of justive, the expunging was an injustice to the defence. We could not test the credibility of witnesses."

Anwar, 52, was sacked by Mahathir on September 2, 1998. He was detained 18 days later, initially under an act allowing detention without trial, after leading mass anti-government protests.

He is separately on trial for sodomy, a crime punishable by up to 20 years, but says he is the victim of a high-level political conspiracy. The government says the courts are independent.

The appeal continues Wednesday.