Lawyer Lee Suet Fern has been suspended from practice for 15 months after she was found guilty of misconduct over the handling of the last will of founding prime minister Lee Kuan Yew.

Chief Justice Sundaresh Menon wrote in the judgment today that Mrs Lee was guilty of misconduct "unbefitting an advocate and solicitor,'' Channel News Asia reports.

He also said her culpability was "at least moderately high,'' while the harm caused by the misconduct was "at the lower end of the moderate range".

The decision was made by the court of Three Judges, comprising Chief Justice Menon, Judge of Appeal Judith Prakash and Justice Woo Bih Li.

The court is the highest disciplinary body dealing with lawyers' misconduct.

During hearings in August, the Law Society sought to have Mrs Lee struck off the roll for professional misconduct.

Mrs Lee, the wife of Lee Kuan Yew's son Lee Hsien Yang, has been a lawyer for more than 37 years and is listed online as a director at Morgan Lewis Stamford.

Mrs Lee's lawyers, Senior Counsels Kenneth Tan and former Attorney-General Walter Woon, urged the Court to dismiss all the charges against her, arguing that Mr Lee Kuan Yew knew what he was doing.

The disciplinary tribunal had earlier found Mrs Lee guilty of two charges of grossly improper conduct as a lawyer.

Lee Kuan Yew had written seven wills, the first six of which were prepared by his lawyer Ms Kwa Kim Li.

However, Ms Kwa was not involved in the last will, with Mrs Lee purportedly handling it as Ms Kwa was away and Lee Kuan Yew had asked for his first will to be used as his final will. The will was prepared and executed in December 2013.

The last will differed from the sixth will as it restored the equal shares of the estate among Mr Lee Kuan Yew's three children - Prime Minister Lee Hsien Loong, Lee Hsien Yang and Dr Lee Wei Ling. In the sixth will, Dr Lee Wei Ling was given an additional 1/7 share of the estate compared to her two brothers.

The last will also reintroduced a clause asking for the late Mr Lee’s house at 38 Oxley Road to be demolished.

A draft of this last will was sent by Mrs Lee to Mr Lee Kuan Yew on Dec 16, 2013, copying Mr Lee Hsien Yang and Ms Kwa. Ms Kwa "for some unknown reason" appeared not to have received the email, according to the material facts.

On the question of whether there was an implied retainer between Mrs Lee and Mr Lee Kuan Yew, the court noted that Mrs Lee had given "two inconsistent explanations" of the circumstances that led her to send the email.

The first explanation was that Lee Kuan Yew had instructed Mrs Lee to revert his will to the first.

This was inconsistent with a second explanation, which was adopted only during disciplinary proceedings, that he had instead communicated those instructions to Lee Hsien Yang, who had then asked Mrs Lee to make the necessary arrangements to give effect to those instructions.

The court found that the second explanation was the true position as there was "no plausible reason" why Lee Kuan Yew would have "abruptly approached" Mrs Lee to seek her assistance in reverting to his first will, given that he "regarded Ms Kwa as his solicitor for matters pertaining to his estate generally.''

Furthermore, Mrs Lee would otherwise not need to copy Lee Hsien Yang in the email and invoke him in carrying out Lee Kuan Yew's instruction. Neither would she need to copy Ms Kwa in the email to ask her to produce the draft last will attached to the email.

The court also noted that there were no further messages between Mrs Lee and Mr Lee Kuan Yew after the email. Instead, they were between Mr Lee Hsien Yang and Mr Lee Kuan Yew.

The court also rejected Mrs Lee’s account that Lee Hsien Yang had sent the draft last will to her and she merely forwarded it to Lee Kuan Yew "without even opening it.''

The court found that the draft came from Mrs Lee, who had been involved in drafting the first will, and not from Lee Hsien Yang.

Lee Hsien Yang was likewise "not telling the truth when he said that he was the one who had forwarded" the draft last will to Mrs Lee, said Chief Justice Menon.

In weighing Mrs Lee's culpability, the court considered several factors in favor of a heavier sentence, including her "singular focus in achieving what her husband wanted, oblivious to (Mr Lee Kuan Yew)’s interests".

This was weighed against the absence of an implied retainer between Mrs Lee and Lee Kuan Yew, "which somewhat attenuated the degree of trust that (Lee Kuan Yew) placed in (Mrs Lee).'' That said, this factor was "of limited weight" as Lee Kuan Yew was "ultimately led by Lee Hsien Yang, with (Mrs Lee)’s knowledge" to rely solely on her representations about the draft last will, which turned out to be untrue.

The court also ruled that Mrs Lee "did not act dishonestly in her dealings" with Lee Kuan Yew, although this factor was likewise of "reduced weight" as she acted with "a degree of dishonesty" in the disciplinary proceedings by seeking to downplay her participation in the preparation and execution of the last will.

Lee Suet Fern is the wife of Lee Kuan Yew's son Lee Hsien Yang. She has been a lawyer for more than 37 years.

Singapore lawyer Lee Suet Fern suspended for misconduct in handling Lee Kuan Yew will