Six men are already being held in custody charged with the killing, thought to be linked to a longstanding feud between the Hells Angels and Finks bikie gangs.

They are Daniel Mark Jalleh, Ross William Montgomery, Kyle Lloyd Pryde and brothers Husain Ali Alzuain, Mohamed Alzuain and Musa Ali Alzuain.

The seventh accused, Nicholas Sianas, made no application for bail when he came before Adelaide Magistrates Court on Thursday.

All will return to court in March along with another man, Jake Byron Martin-Herde, who has been charged with assisting an offender.

Mr De Ieso's killing is believed to be a case of mistaken identity.

CCTV footage previously released by investigators showed nine men walking towards the front of his Adelaide workshop, with at least two of those carrying guns.

The men opened fire, killing Mr De Ieso, before running from the scene.

But police said the 33-year-old had no links to either the Hells Angels or the Finks and was just an "innocent bystander".

Australian Associated Press