Moses Matovu was attacked in Kibuli early on September 24, 2026, and later died at Kibuli Hospital.
Police say he had visited a woman before the pair encountered another man allegedly linked to her.
The woman is in police custody while investigators pursue the male suspect who allegedly fled.
Police say the circumstances of the confrontation remain under investigation.
Veteran musician Moses Matovu drove into Kibuli in the early hours of Thursday, September 24, 2026, in what would become his final journey.
The 77-year-old Afrigo Band co-founder parked his Range Rover, registration number UAR 982H, by the roadside before walking with a woman into a nearby corridor at Kibuli Market Zone B in Makindye Division.
What happened next remains the subject of a police investigation.
Police now believe Matovu had gone to the residence of a woman they describe as his girlfriend at about 5.30am.
As the pair left the residence, investigators say they encountered another man who had previously been in a relationship with the woman.
A confrontation followed.
"Preliminary information indicates that the incident may have arisen from a physical altercation," Kampala Metropolitan Police spokesperson Rachael Kawala said.
Police have not disclosed what triggered the confrontation, who struck Matovu or what weapon, if any, was used.
But Matovu suffered serious injuries.
A boda boda rider later rushed him to Kibuli Hospital, where doctors tried to save his life. He later died from his injuries.
The death has left detectives piecing together the movements of Matovu, the woman and the man now being pursued by police.
The woman has been identified as Rose Tumusiime. Sources said she was being held at Kabalagala Police Division, although police had not publicly named her by press time.
Kawala confirmed that the woman who was with Matovu had been arrested and was helping detectives with investigations.
Police have also identified the male suspect.
"The male suspect has been positively identified and is believed to have fled the scene," Kawala said.
She said police were pursuing him to establish the full circumstances surrounding Matovu's death.
The latest account marks a shift from the first information released after the attack.
Earlier on Thursday, police said Matovu had been attacked by unknown assailants at Kibuli Market Zone B. Kabalagala Police Station then opened a suspected murder investigation.
Initial reports also suggested that the veteran musician had been attacked while heading for morning prayers.
Police investigations have since focused on the confrontation involving the woman and the second man.
Kawala cautioned that the findings remain preliminary.
"However, the exact circumstances surrounding the confrontation and subsequent death are yet to be fully established," she said.
Detectives are now comparing witness accounts and reconstructing the events before and after the attack.
Police have asked the public to avoid speculation as the investigation continues.
"We call upon members of the public to remain calm and allow investigators to conduct their work without interference," Kawala said.
Matovu's death ended a music career that stretched nearly six decades.
Born on June 19, 1949, Matovu entered professional music in 1967. He later performed with the Police Band and Cranes Band before helping establish Afrigo Band in 1975.
He became one of the group's most recognisable figures as a bandleader, vocalist, composer and saxophonist.
Matovu remained active as Afrigo Band marked its 50th anniversary in 2025.