Kenyan authorities are working closely with the UK government to investigate the killing of a British soldier during an attempted robbery last week.
A senior investigating officer, who spoke to the BBC anonymously, said British and Kenyan investigators have visited the crime scene just outside the capital, Nairobi.
The team is "close to making arrests", the officer added.
He said Maj Kevin McCool was on a motorcycle trip off-base when he was attacked by a group of gunmen.
A group of men trailed and ambushed him when he drove into Vet Farm, a popular hiking spot about 25 km (16 miles) from Nairobi.
The men demanded money and his phone before one of them drew a gun, the officer said.
Maj McCool's father previously told the PA news agency that his son thought the gun was a dummy.
Witnesses told police that the soldier was rushed to hospital, where he was pronounced dead.
British Defence Secretary Grant Shapps described Maj McCool's death as a "tragic loss".
The British army has a permanent base north of Nairobi where it trains its forces.