A lawyer who was rapped by a district judge in 2016 for commenting on the breast size of a molestation victim has been slapped with a fine by a disciplinary tribunal over a different matter - his behaviour towards two police officers.

Mr Edmund Wong Sin Yee pleaded guilty to two charges of unprofessional conduct. In the first instance, Mr Wong told Staff Sergeant Lin Yuheng in a telephone conversation in August 2015 that his client would be "happy to sell her body" to pay for legal fees so the lawyer can drag the case for a year.

In the other case, Mr Wong accused Inspector Stanley Qiu of being "cocky" and shouted a four-letter word at him over the phone in May 2016. The officer was investigating one of Mr Wong's clients for suspected extortion.

The tribunal, appointed by the Chief Justice and comprising Senior Counsel Molly Lim and lawyer Carrie Seow ruled the language Mr Wong used as "highly inappropriate, objectionable and totally unacceptable" in its report released last week.

The tribunal recommended that he be fined $3,000 for each of the two offences and pay $3,000 in costs. The recommendations will be considered by the Law Society's governing council.

The lawyer had previously been in trouble for his behaviour in court. In 2016, a disciplinary tribunal fined him $3,000 and ordered him to pay the Law Society $6,500 in costs.

Besides uttering an expletive in court, he had made a snide remark during a vice-related trial when he asked the prosecution witness if she had found the sexual act she performed on a customer "shiok", a colloquial term for enjoyable.

As for the breast size comment, a disciplinary tribunal which probed the case last year referred his misconduct to the Court of Three Judges, which is due to hear the case in May.

In mitigation, Mr Wong, through lawyer Bala Chandran, apologised for the language used on the two officers, explaining it was not meant to offend but was uttered in the heat of the moment out of frustration in his dealings with police for his clients.

Lawyers Chandra Mohan Rethnam and Doreen Chia, who prosecuted the case for the Law Society, called for fines on the higher end of the $20,000 spectrum to be imposed to reflect reprobation of his conduct. The tribunal made clear that using offensive words out of frustration did not justify the misconduct as there are other avenues for him to deal with any complaints he had against the police officers.

"The police and other law enforcement agencies and members of the public are entitled to expect (a lawyer), when dealing with them, to behave in a manner befitting his professional standing both as an officer of the Supreme Court and as a member of an honourable profession," said the tribunal.