The inquest of two policemen and a security guard killed more than six years ago allegedly caused by another policeman Tsui Po-ko began yesterday. It was revealed that a constable killed in 2001 might have escaped death had he not swapped lunch time duties with his colleague.

The inquest, expected to last for 37 days, will be one of the longest in Hong Kong. More than 100 witnesses would be summoned and more than 300 boxes of material evidence presented. It will examine the deaths of constables Leung Shing-yan, Tsang Kwok-hang and Tsui and the Pakistani security guard, Khan Zafar Iqbal.

The links among these deaths were exposed last March when Tsui and Tsang were killed and his colleague Sin Kar-keung severely injured in a gun battle in Tsim Sha Tsui. Preliminary police investigation found that Tsui shot Tsang. But before he died, Tsang fired back and killed Tsui.

Results of further investigation suggested that Tsui, who had performed excellently in police promotion examination, had used the gun of Leung who was killed on March 14, 2001 in a Hang Seng Bank robbery in the same year to kill the security guard and in the Tsim Sha Tsui shoot-out.

The first few days of the inquest will focus on the killing of Leung.

Experts will be asked to give account of Tsui's psychological status.

Police officers, who testified yesterday, said the events leading to Leung's killing were rare.

Lam Chun-fai, constable of the crime reporting room in Lei Muk Shue (LMS) district, where Leung was stationed, said he had received a fake noise complaint at noon on March 13, one day before the killing.

The complainant from Lei Muk Shue estate left a mobile phone number that could not be reached, and Lam said he rarely received noise complaint at noon.

On the day of killing, Tsuen Wan police station officer Siu Man-kei had received another complaint from a man surnamed Tsang that the hi-fi music system of a flat in Shek Wai Kok Estate was noisy.

Siu said the complainant, aged about 30,who could speak fluent Cantonese in low-pitched voice, had not called the crime reporting hotline, but the phone number used by police internal communication.

Siu told the complainant that the matter should be handled by LMS district, and gave him the district police station phone number.

The man then called the LMS station at 12:05 pm.

Leung, on the morning duty shift, was supposed to have lunch at 12:30.

But the officer, Lam Yam-man said Leung had swapped lunchtime with colleague and finished it earlier because of the change of duties.

The colleague, who was also responsible for Lei Muk Shue Estate, was therefore not able to handle the complaint, and Leung volunteered for the task.

Lam was notified about half an hour later that Leung had collapsed. He found out that Leung had already stopped breathing, and his gun and bullets were stolen. He rushed to the scene.

Leung, aged 24 at that time, left his girlfriend Cheung Ling-chi and son, now five years old.

Cheung lived together with Leung in Tai Po in 2000.

Cheung said Leung had borrowed about HK$30,000 from police for moving to Tai Po and had taken some credit card loan. Leung had also gone to Macao, but Cheung didn't know the purpose of his visit.

She stressed that Leung had no financial problem as he earned more than HK$19,000 a month and used to give his mother HK$4,000 a month.

She said Leung had no ill-feelings with colleagues, and did not know the other cops involved in the killings.

The hearing will continue today. Coroner Michael Chan, coroner's officer Arthur Luk and the jury will make a site visit to Shek Wai Kok Estate in Lei Muk Shue, where Leung was killed six years ago.