Mr Justice Woo Kwok-hing, a vice-president of the Court of Appeal and chairman of the Electoral Affairs Commission, will supervise the work of a three-member panel, also appointed yesterday. Its members are judges Pang Kin-kee, Azizul Suffiad and Andrew Chung On-tak. The appointments were made by Chief Executive Donald Tsang Yam-kuen, who said the three had a wealth of experience.

A lawyer, who asked not to be named, described the three as 'fair and hard-working'.

Members of the legal fraternity had heard judges Pang and Suffiad were likely candidates for the panel, but the appointment of Mr Justice Chung was a surprise.

Mr Justice Woo's appointment will take effect next Thursday, while that of the other judges takes effect immediately. The commission will authorise law enforcement agencies to intercept phone, e-mail and postal communications and carry out covert surveillance.

Mr Justice Woo said he was conscious of the need 'to ensure that all interception and surveillance activities to be employed by law enforcement agencies must be in accordance with the law and will not be unjustifiably undertaken'.

'I well appreciate the rights cherished by individuals in Hong Kong against intrusion by any such activities and the significance of protection of such rights,' he said.

Civic Party lawmaker Ronny Tong Ka-wah said the arrangement put the city's judicial independence at risk. He had sought in vain to amend the legislation to stop judges hearing court cases while serving on the panel.

'The government refused to include that anywhere in the statute and said it was up to the chief justice to decide, based on the caseload of the judges ... The whole set-up blurs the line between the judiciary and the executive,' he said.

The party has warned that judges sitting on the commission will be privy to government investigations that may have a bearing on cases they are hearing.

Democratic Party legislator Martin Lee Chu-ming urged the judges not to forge close ties with law enforcement officers who may appear before them regularly to request authorisation for operations.

The government revealed during debate on the bill that in a three-month period this year, the police, ICAC, customs and immigration departments undertook almost 200 cases of interception of communication and surveillance of a nature requiring the judges' authorisation under the new law.

The government had the option of appointing up to six judges to the panel. Some observers said it may have had difficulty getting more members of the judiciary to agree to serve on the panel because of the intensive integrity checks appointees undergo.

Secretary for Security Ambrose Lee Siu-kwong said: 'Hong Kong's newly enacted law compares favourably with similar laws in other common law jurisdictions as far as protecting people's freedom and privacy is concerned.'