On 10 March 2003, at Singapore's Choa Chu Kang, 32-year-old Diana Teo Siew Peng (赵秀萍 Zhào Xiùpíng) was forcibly thrown off the tenth floor of her flat and she fell to her death.

On 10 March 2003, officers of the Singapore Police Force responded to a report that a woman had fallen to her death from her flat at Choa Chu Kang.

[19] On 23 February 2004, the trial of Harith Gary Lee took place at the High Court, with the judge Woo Bih Li presiding over the case.

Jaswant Singh led the prosecution while both Goh Teck Wee and David Rasif represented Lee as his defence counsel.

[20] One of the prosecution's first witnesses was Staff Sergeant (SSGT) Ishak bin Mohamed of the Singapore Police Force.

SSGT Ishak also stated Lee smelt of alcohol and aggressively resisted the cops' attempt to arrest him.

[26] 34-year-old Rita Goh Lye Keow, a close friend of Teo, also testified that on the night before her death, Teo came to her flat in Woodlands to spend the night and she told Goh about the unhappy relationship she had with Lee, who she thought was too introverted and over-possessive and did not give her much privacy; the relationship itself was smooth for the first four months before the first of its cracks begun to surface.

The third and final time was when both Leong and Goh went their separate ways, the couple was already at the parapet, with Lee holding on to Teo's legs.

Lee claimed that at the time he supposedly threw Teo off the tenth floor, he was just trying to cling on to her legs and stop her from jumping off but it was too late.

Lee's defence counsel even tried to suggest to the witnesses, specifically the policeman SSGT Ishak and Leong Siew Choon that they never heard or saw the defendant intentionally causing the victim to fall to her death.

[30][31][32] On 10 March 2004, the date of Diana Teo's one-year death anniversary, the trial judge Woo Bih Li made the unusual decision of personally visiting the crime scene (the tenth floor of Teo's flat) in order to verify the claims of Gary Lee and the prosecution witnesses, so as to determine whether the victim was murdered or died in the manner of suicide.

Justice Woo also pointed out that even after forcibly meeting Teo at her workplace, Lee's rage had not subsided and as a result, by intentionally pushing the victim off the tenth storey of her residential block and causing the death of 32-year-old Diana Teo Siew Peng, Lee had, in Justice Woo's words, "sealed her fate and his own".

The execution of Lee was not revealed until two months later in June 2005, when a crime correspondent for the national newspaper The Straits Times commented that the authorities should not withheld any announcement of judicial hangings for the sake of public interest that concerned about whether justice was served.

[46] Two months after Harith Gary Lee was put to death, in June 2005, Singaporean crime show Crimewatch re-enacted the Diana Teo murder case and aired it on television.

Rasif, who had fled Singapore with his ill-gotten monetary gains, remains on the run as of today and was still wanted by Interpol for his offences.

It was reported that despite the couple's divorce in 1995, Ong still loved his ex-wife and never gotten over her, and he was still carrying a photograph of himself and Teo in his wallet.