Cheung, 54, also admitted driving a car with a non-complying number plate and that he had 'overestimated my drinking capacity'. But he insisted he was sober when he crashed his car after swerving to avoid a dog on October 19 last year.

He had refused to give a blood sample because he believed a breath test he had already given - showing his blood-alcohol level was four times the legal limit - was enough.

Cheung refused to comment on whether his conviction was another blow to RTHK after disc jockeys and producers were accused of or admitted filing false fee claims, and after the resignation of its former chief in a scandal over a karaoke hostess.

'It is a separate incident and I don't want to comment. But I want to apologise to my colleagues who were bothered by this,' he said.

Former director of broadcasting Chu Pui-hing also warned on the hazards of drinking when he stepped down after being photographed hiding behind a karaoke hostess. 'Alcohol is not conducive to good behaviour,' he said.

RTHK Program Staff Union chairwoman Janet Mak Lai-ching said yesterday's conviction would not damage the image of RTHK or affect staff morale because the crash happened when Cheung was off duty and therefore did not affect his official role.

Ms Mak said staff were more worried about the delay of the long-awaited public consultation on public service broadcasting, which touches on RTHK's future.

The Civil Service Bureau said it would not comment on an individual case when asked whether Cheung would be subjected to disciplinary action.

Each department had its own standard internal procedure to follow, a spokesman said.

The court heard yesterday that Cheung was arrested for drink-driving after the breath test but he did not give a blood sample for another alcohol test when police asked him to do so in the emergency room of Prince of Wales Hospital.

Magistrate Timothy Casewell imposed an extended disqualification period, saying Cheung's refusal to give a blood sample was meant to disguise the extent of his alcohol level and this would be reflected in the sentence.

Cheung's lawyer, Cheung Wing-leung, said his client's judgment was not impaired but the magistrate questioned this, saying Cheung's breath test showed a high level of alcohol content.

The lawyer said his client was remorseful and had openly apologised on many occasions.

The incident had created embarrassment, impaired his reputation and might lay him open to disciplinary action.

He said Cheung was traumatised by his first traffic accident in 25 years of driving and the chaos at the hospital, where he was mobbed by the media, had interfered in communication between him and the police.