The administration of justice could be at risk because of the poor quality of part-time court interpreters, say two legal and translation professionals.
A barrister who speaks Punjabi says he notices flaws in court interpretation on almost every occasion when the professional service is required.
And a linguist specialising in court interpretation blames the judiciary's recruitment process and unsatisfactory remuneration, which can be as low as a tenth of the market rate for experienced translators.
She also censures the judiciary for being reluctant to introduce an accreditation system to ensure quality.
The critical appraisal of the standard of court interpretation came after the High Court in August, because of errors made by an interpreter, quashed the conviction of a Pakistani man jailed for creating a bomb.
In that case, an interpreter wrongly translated the term "with intention to induce".
"I often interrupt the interpreter and suggest a better alternative immediately without letting the matter get out of hand," the Punjabi-speaking barrister said.
One example he cited was the lack of a Punjabi word for "appeal". He had heard an interpreter repeating the term in English to the defendant. He said it was not uncommon for judges to show signs of impatience as the interpreters translated questions and responses.
Ester Leung Sin-man, who sits on the advisory committee of the Multilingual Interpreters and Translators Association, said: "It is at the court level where interpreters are found not really delivering their best services.
"But before the trial, it could be even more horrible."
Leung, a trainer of court interpreters, said the judiciary managed Chinese-English interpretation well, but the handling of ethnic-minority languages was disappointing.
She had "serious doubts" about the judiciary's screening process for new, part-time recruits. Candidates took a brief translation test and the exam invigilators might not be able to speak the language being assessed, she said.
For unusual languages, the judiciary might even fail to find an interpreter, she said. In 2010, a hearing involving the murder of a Mongolian was adjourned after an interpreter failed to turn up.
"I have been asking the government to set up an accreditation system to provide interpreters with proper channels to be trained and to be qualified to do the job," she said. "But of course it's not happening. It seems to me that they don't like to see changes. And they are worried that it might cost them money.
"They are saying that this is not the majority [of people] anyway," Leung said, adding that the judiciary seemed to ignore the fact that an appeal could be even more costly.
She suggested the judiciary make use of information technology to tap into the pool of accredited court interpreters overseas. An interpreter who is physically in another country could work through videoconferencing, she said.
Leung says part-time court interpreters are paid HK$250 an hour. The fixed pay is a disincentive, as interpreters are not remunerated according to their ability.
Outside courts, she says, freelance interpreters are paid more than HK$700 an hour and the experienced get HK$2,500.
The judiciary keeps a list of 377 part-time interpreters for 57 languages and dialects, including 206 for Asian and Middle Eastern tongues and 16 for African ones.