So lets put the entire news article here.
What we know: While this cluster began as a workplace outbreak, on 25 June it was reclassified by the health department as a family cluster in the suburb of North Melbourne.
The first person diagnosed was a staff member at the H&M store who also attend the Black Lives Matter protest on 6 June, but was not considered to be infectious at the time. Two days later a second staff member contracted the virus. They also attended the protest but are believed to have been infected at the store.
By 26 June the cluster had grown to 15, the majority household contacts of a staff member.
While some reports have suggested that the “North Melbourne” in the cluster’s name refers to the region of “northern Melbourne”, the DHHS has twice confirmed to Guardian Australia that the name does, in fact, refers to the suburb of “North Melbourne”. However, this does not necessarily mean that all, or even most, associated clusters are actually located within that suburb.
On 25 June a new “Brimbank Family” cluster was declared, which grew to six cases over the next few days. On 29 June the health minister said a link had been found between this cluster and the North Melbourne outbreak.
I says everything in the first paragraph.
Yes, the first person infected aka the person who brought the virus to the workplace was a BLM protestor...That person picked it up through unknown source in the same period they attended the protest...