An autopsy on the body of Briton Campbell Scott is inconclusive.
Officials said soft tissue injuries found on Scott's body are deemed too minor to kill him.
This forced the pathologists to pick samples for further tests.
The autopsy was conducted on the body of Scott at a mortuary in Makueni on Thursday.
This threw investigators to the drawing board in their quest to establish the cause of the death. The autopsy was conducted by Government Pathologist Dr. Richard Njoroge.
His family was present.
The autopsy failed to reveal what caused his death, forcing them to pick samples for tests at the government chemist.
The police had earlier found injuries to suggest he was strangled or hit by a blunt object.
But this narrative changed later on.
Investigators said they believe the killers of Scott are hiding in Mombasa.
The motive is yet to be known.
According to police, after disposing of his body in a forest in Makueni, they proceeded to Mombasa where they are hiding.
Police also believe the killers were after his money.
They had held him for days in a house in Pipeline area in Nairobi before they killed him and transported the body to Makongo forest where it was discovered on February 22.
There are possibilities the killers also accessed his bank accounts. Police are pursuing that angle.
Police say Scott was not new in Nairobi.
There is an indication he had visited the city earlier on.
Scott went missing from his hotel in Nairobi on February 17 before his body was found in a forest days later.
Scott’s body was Monday February 24 positively identified at the Makueni County Referral Hospital, where it had been lying for two days.
It was found on Saturday, February 22, in a forest stuffed in a sack and taken to the local mortuary where officials identified it.
Two suspects, including a waiter at a club in Westlands and a taxi driver, have been arrested, and they are under probe for murder.
Scott, 58, and a senior director with data analytics company Fico, arrived in the country on Sunday, February 16, accompanied by a colleague, to attend a three-day workshop in Nairobi at the JW Marriot Hotel in Nairobi.
Detectives from the Directorate of Criminal Investigations (DCI) said Scott was captured on CCTV leaving the JW Marriot Hotel with a man, dressed in a white T-shirt and a light pair of blue jeans, before they boarded a vehicle.
Investigations led the detectives to arrest the taxi driver, and his vehicle was confiscated. In his statement to the police, the man said he had dropped the Briton together with other people at Pipeline Embakasi.
That was the last time he was seen. Police are tracing the people he was with that day.
CCTV footage captured Scott dressed in cargo pants and a blue shirt before walking out.
He came back at around 4pm and was seen talking to the hotel guards.
The following day, February 17, he left at around 11.15 am and never came back.
Immediately he went missing, the matter was reported at Parklands police station. The DCI later involved the Interpol in the joint investigation and operation to trace him.
His call records were then retrieved to establish those he spoke to before he went missing.
At least six people recorded their statements with the police, including the hotel staff and security personnel.
