SINGAPORE - Any minister accused of improper conduct must clear his name publicly, Prime Minister Lee Hsien Loong said on Tuesday (Aug 1).

He or she must not allow the allegations to fester and affect the reputation of the Government, PM Lee said in a written parliamentary reply to Mr Chen Show Mao (Aljunied GRC).

In it, he laid out the guidelines and ways political appointees should publicly address allegations against them.

"If it is a serious allegation, I would expect the Minister to take court action for defamation, unless there are other special considerations," said PM Lee.

The minister may also have to give an account of the events in Parliament, particularly if the matter concerns the discharge of his or her public duties and is of public interest.

"These are not mutually exclusive options. In all cases, there must be public accounting," he added.

Mr Chen had asked about the circumstances under which a minister or political appointee should defend his reputation in his official capacity in the courts, or refrain from such court action and address allegations publicly, like in Parliament.

PM Lee said he had addressed this issue in his ministerial statement delivered on July 3 in Parliament.

The statement was made in response to allegations from his younger siblings. Mr Lee Hsien Yang and Dr Lee Wei Ling had accused PM Lee of abusing his power and blocked the demolition of the family home at 38, Oxley Road, after the death of their father, founding prime minister Lee Kuan Yew.

He had said then: "In normal circumstances, I would surely sue because the accusations of abuse of power are so grave. But suing my own brother and sister in court would further besmirch our parents' names."

PM Lee also said he did not enforce his full legal rights, as his priority was for the family dispute to be resolved privately.