The case was opened by Nathi Ngwenya of Ngwelela Security Services, the company that provides security for AmaZulu's home matches at King Zwelithini Stadium in Umlazi.
This came after the pair tangled following a 3-3 draw between the clubs at the venue on September 16.
After the final whistle, two Masandawana fans in club regalia invaded the pitch. When security started taking them away, Mosimane intervened as he felt they were being too rough.
A scuffle ensued with Ngwenya and police needed to step in before Downs team manager Peter Ndlovu ushered Mosimane away.
Mosimane defended his actions in the post-match press conference, and denied he threw a punch during the melee.
Durban-based SAPS lieutenant Thulani Zwane says the matter is still being probed.
"We are further doing our investigation and we are not done," Zwane told KickOff.com.
"At this point in time we haven't also given ourselves a time scale of how long the investigation will take because the Magistrates' Court is faced with many court cases.
"When we are done with our investigation the docket will go to court and the magistrate will have to be given time to make a decision.
"But as of now there are so many dockets in front of him."
Mosimane declined to comment further on the issue after his team concluded their trip to KwaZulu-Natal with a 1-0 win over Golden Arrows at Princess Magogo Stadium in KwaMashu on September 19.
"No, no, no, we are not talking about it. I don't have a comment on that, okay," Mosimane said.