Hoosen Dhoda was gunned down after a group of men stormed the Royal Travel Agency in Problem Mkhize (Cowey) Road in an apparent armed robbery last week.
A crack team of private investigators and police arrested three men in connection with the murder at the weekend, and a fourth was taken into custody on Tuesday.
eThekwini Metro policeman Sandile Dlamini, 27, together with Sipho Mbele and Bonokwakhe Magubane, were the first to be taken into custody and appeared on Monday.
Police and members of the Magma Security investigations team had searched for Ayanda Dlamini, eventually tracing him to the Applebosch settlement in the vicinity of Wartburg in central KwaZulu-Natal.
He cut a sad figure as he stood in the dock wearing a T-shit, dirty trousers and socks without any shoes. He applied for legal aid and the matter was adjourned.
He will join his co-accused when they appear before the court on Monday.