Masked robbers shot dead a man in front of his husband before making off with his designer watch collection, police said.
Guy Hedger was killed in the early hours of 30 April after at least two intruders entered his £1 million home in the village of St Ives, near Bournemouth.
Dorset Police responded to a report that the 61-year-old marketing executive had been shot with a shotgun. He was pronounced dead shortly after arriving at hospital.
Investigators said they were hunting for two suspects in connection with the raid, which they believe may have been pre-planned. They said the death was being treated as “aggravated burglary”.
The victim's partner of 12 years, Simon-Pierre Hedger-Cooper, 48, who was in the house at the time, had been deeply affected by the incident and is being supported by specially-trained officers, police said.
The thieves escaped with the watches and other jewellery, they added.
“We are still trying to establish a motive for the intruders and why this particular address in Castlewood was targeted," Detective Chief Inspector Sarah Derbyshire said.
“We believe there was an element of preplanning involved. Therefore we would urgently like to hear from anyone who may have seen people or vehicles acting suspiciously in the area directly before or during the days leading up to the incident.
“This may have involved people in the area in general or paying particular attention to the specific house. Any small detail may help us with our investigation.
“Currently, we do not believe the offenders were known to the victim. However, we continue to investigate all lines of inquiry.”
The force said Mr Hedger’s family have asked for privacy at “this deeply traumatic time”.
But a spokesman for his employer, the insurance company Liverpool Victoria (LV=) paid tribute to him.
He said: "We were all shocked to hear that our friend and colleague Guy Hedger, LV='s marketing and brand director, died over the weekend in such tragic circumstances.
"An extremely talented marketer, Guy was instrumental in building the LV brand and he will be sorely missed by many."
Additional reporting by PA