Security officer Tan Choon Lai, 56, was believed to be intoxicated when he rode his motorcycle in a slip road of the Pan-Island Expressway (PIE) into Bukit Timah Expressway shortly after midnight on July 10, 2017.
His motorcycle crashed into the left side of a taxi before hitting a guard railing.
The Singaporean, who suffered multiple injuries, was taken to the National University Hospital and died at around 3am.
Station Inspector Kenny Cheong Chyuan Lih allegedly forged four statements - two from the taxi driver and one each from a witness and Mr Tan's sister.
During hearings into the reopened cases that took place last week, Coroner Marvin Bay said that while the sources of the forged contents were unclear, Station Insp Cheong had told investigators that all the statements were forged following verbal conversations with the subjects.
Delivering his findings last Monday, Coroner Bay said Mr Tan had a grossly elevated post-mortem blood alcohol level of 233mg of alcohol per 100ml of blood.
This is almost three times the legal limit of 80mg.
The coroner said: "(This) would have likely caused severe intoxication, such as drowsiness, loss of coordination or poor judgment.
"It is probable that in his intoxicated state and impairment of his faculties, (Mr Tan) had either lost control of his motorcycle or inattentively swerved his vehicle onto (the taxi), and then swerved right before colliding into the guard railing.
The coroner found Mr Tan's death to be a traffic misadventure.
On Aug 11, 2015, at around 6am, Mr Tan Ser Chuan, 57, a Malaysian, was riding his motorcycle along Ayer-Rajah Expressway towards Marina Coastal Expressway when he skidded and fell.
A taxi ran over him and drove off. The cabby went to his company's servicing centre but did not make any repairs there. He later drove to a private repair shop in Eunos.
An eyewitness alerted the police and a paramedic pronounced Mr Tan dead at the scene at 6.20am. He was later found to have died of blunt force trauma to his head and chest.
The cabby was caught after investigators viewed expressway camera footage of the incident.
The taxi was seen making an abrupt swerve to the left when it reached the spot where Mr Tan and his motorcycle were lying.
The court heard that the front headlamps of the taxi were then seen jerking up and down, suggesting that the vehicle had run over something.
The cabby was sentenced to five months' jail, fined $1,000 and disqualified from driving all classes of vehicles for three years.
Station Insp Cheong had allegedly forged statements from the cabby and Mr Tan's daughter.
Coroner Bay said last Monday that subsequent investigations showed the forged documents were adapted from other statements recorded from the pair. He found Mr Tan's death to be an unfortunate traffic misadventure.
Mr Tan Hock Hai, 40, had consumed alcoholic drinks shortly before he drove his car along the PIE on Nov 2, 2016.
He lost control of his vehicle and crashed into some guard railings.
He suffered multiple injuries including a severed left arm and was pronounced dead at the scene at around 2am.
Last Monday, Coroner Bay said Mr Tan was found to have a blood alcohol level of 271mg of alcohol per 100ml of blood - more than triple the limit of 80mg.
Station Insp Cheong allegedly forged a statement from Mr Tan's wife. Coroner Bay said that in the fabricated statement, she stated that Mr Tan would meet clients or friends, at least once a week after work, in the Jurong area. And she purportedly believed the collision had occurred while Mr Tan was on his way home after meeting his clients or friends.
This fake statement added that she had on a few occasions detected the presence of alcohol in Mr Tan's breath, after he had driven home.
When the Internal Affairs Office of the Singapore Police Force interviewed her, she did not recall Senior Insp Cheong asking her to sign any statements.
The coroner noted that the policeman said the contents of this forged document were based on verbal conversations.
Coroner Bay found Mr Tan's death to be a traffic misadventure.
Deliveryman Tan Kiah Huat, 62, was riding a motorcycle shortly before he was involved in a traffic accident on Dec 21, 2016.
A man was driving a lorry in Jalan Bukit Merah towards Alexandra Road that day when he felt an impact on the rear of his vehicle.
Mr Tan, a Singaporean, was found lying on the road and the police were notified at 3.25pm. He was taken to Singapore General Hospital (SGH) and died of multiple injuries about an hour later.
Station Insp Cheong allegedly prepared a statement purportedly from Mr Tan's sister, who cannot speak or hear. In the statement, she supposedly said her brother had been behaving normally before his death and he had no suicidal tendencies.
It turned out that the statement had been fabricated.
A sign language interpreter later communicated with the woman and learnt that she could not recall being approached by Station Insp Cheong to give her statement.
Coroner Bay said last Monday that it was uncertain what source material the policeman had referred to in the document.
He added: "Despite the fact of the conditioned statement of the next of kin being forged, (it concerned only) background information on Mr Tan's health and his absence of suicidal intent... I reconfirm my verdict of Mr Tan's demise from an unfortunate traffic misadventure."
KNOCKED DOWN BY LORRY
On Jan 16, 2016, Bangladeshi construction worker Mahamudul Islam Zia Md Sikat Ali, 36, was seen running across Kitchener Road in Little India before a lorry knocked him down. He was taken to Tan Tock Seng Hospital and died of his injuries two days later.
Last Monday, the court heard that Station Insp Cheong allegedly forged a statement from an eyewitness for this case. Investigations revealed that the contents of this forged document were similar to that of an earlier written statement taken by another investigation officer, who came from a team that dealt with non-fatal accidents.
Coroner Bay said the other investigation officer had not been aware of Mr Mahamudul's death at the time she recorded the statement from the witness. She had been required by existing protocol to hand the case over to Station Insp Cheong when Mr Mahamudul died.
Mr Bay reconfirmed his verdict that Mr Mahamudul's death was an unfortunate traffic misadventure.
CYCLIST HIT BY TAXI
Mr Ismail Mohd Noh was riding a bicycle near Bedok North Road on Aug 3, 2016, when a taxi knocked him down.
He was taken to Changi General Hospital and died of heart and lung injuries later that morning.
Station Insp Cheong allegedly forged a statement from Mr Ismail's son. The son recalled talking to the policeman only over the phone and had never met him.
Coroner Bay noted last Monday that the son said he had never been asked to sign a conditioned statement. Mr Bay reconfirmed that Mr Ismail's death was an unfortunate traffic misadventure.
HIT WHILE CROSSING ROAD
Singaporean security officer Shaik Shamshudin E.K. Shaik Hussain, 59, was crossing the road near the junction of Victoria Street and Arab Street on Dec 29, 2015, when a taxi hit him.
He was taken to SGH and died of multiple injuries two days later.
Station Insp Cheong allegedly forged three statements - one each from the taxi driver, an eyewitness and Mr Shaik's daughter.
Last Tuesday, Coroner Bay found Mr Shaik's death to be an unfortunate traffic misadventure.
He also said the contents of the forged documents linked to the driver and the eyewitness were found to be similar to earlier statements taken by another investigation officer.
In a statement last Monday, the police said Station Insp Cheong has since been suspended and they were unable to comment further as investigations were ongoing.