The sentence stunned the 59-year-old lawyer's supporters and legal colleagues, who were in the District Court to hear Chief Judge Barnabas Fung Wah pass sentence.

Solicitor Andrew Lam Ping-cheung, 54, was jailed for four years for conspiracy to pervert the course of justice, a charge on which Egan was acquitted.

Businessman Derek Wong Chong-kwong, 38, was jailed for three years on the conspiracy charge and his lover, Mandy Chui Man-si, 26, received a 21/2-year sentence on the same charge.

Chui was also handed a 12-month term for attempted perjury, to run concurrently.

All four plan to appeal against the convictions.

The severity of Egan's sentence for two breaches of Section 17 of the Witness Protection Ordinance - the first successful prosecution under the ordinance - brought cries of 'crazy' from some women supporters in the public gallery.

But Chief Judge Fung described the veteran barrister's actions as a 'blatant breach' of the ordinance and a blow to the administration of justice and the witness protection system. The maximum sentence for the offence is 10 years.

Egan remained stony-faced after sentence was passed, while Lam shook his head.

Defence counsel had described the two lawyers as 'thorns in the side' of the Independent Commission Against Corruption, which brought the charges.

The lawyers were accused of conspiring with Wong, former chairman of listed company Semtech International Holdings, and Chui to use the media and the courts to pressure the ICAC into releasing Wong's secretary, Becky Wong Pui-see, who had joined the anti-graft agency's witness protection programme.

Prosecutors said their aim was to stop Becky Wong giving evidence against her boss in a market manipulation case.

The two lawyers were acquitted of a joint count of conspiracy to disclose the identity of Becky Wong.

Sentencing Egan, Chief Judge Fung noted that the other three defendants had given the barrister the impression that Becky Wong was detained by the ICAC against her will and that this had prompted his decision to file a writ of habeas corpus on her behalf. He acknowledged the accused might not have known that the instructions he received from the three were a sham. But he said Egan did intend to influence the witness' co-operation with the ICAC.

'As an officer of the court, the defendant should act on clients' instructions with vigilance to ensure the system of justice is not abused,' he said. The barrister's attempted disclosure to Ms Chow of the witness' identity - although not amounting to a conspiracy - had aggravated the situation by leading to Becky Wong's name appearing in newspaper reports.

'The defendant never said to the reporter not to report what he said. Why would one speak to a reporter who is collecting information about a subject he knows about? He must know the press is interested in reporting what he said,' said the judge.

Derek Wong was the instigator of the conspiracy, the judge said. But Lam was the one who planned the habeas corpus application. He said that, as a respectable solicitor, Lam had the duty to protect, not abuse, the administration of justice. The behaviour of the solicitor had dealt 'a blow to public confidence in the system of public justice', said the judge.