The Liverpool striker went to the ceremony last week and subsequently tested positive for coronavirus, meaning he will miss key matches for Egypt as well as with the Reds when he returns from international duty.
Photos of the wedding emerged on social media, with little to no social distancing taking place, which has been blamed for Salah contracting the virus.
Mido thinks, despite it being a family member, Salah shouldn't even have been there.
“I know I may be under attack after my next comments, but it has to be that way," he told Al-Nahar TV.
“Mohamed Salah made a big mistake by attending his brother's wedding a few days before the Egyptian national team match, he showed great negligence with the steps taken to prevent the coronavirus and the result was that he was infected.
"He should not have been present at his brother's wedding, especially at that time. The wedding included more than 800 people, and half of them accepted to embrace and kiss Salah.
“The other point here is the silence of all those responsible for the player's negligence, which confirms the fact that the player is still bigger than the national team and this will lead to a great failure."
Mido also believes it is a failure on the part of the country's various football officials, too, for allowing him to attend, with the former Spurs striker calling them "cowards".
“Officials in Egypt did not direct any word of blame or reproach to Mohamed Salah and the harm caused by his negligence to the Egyptian team, and I name each of the Minister of Sports Ashraf Sobhi, Chairman of the EFA Amr Al-Ganayni, the coach of the national team Hossam Al-Badri, and the national team director Mohamed Barakat, all are cowards and fear Mohamed Salah fans who love the Liverpool star, but here I am speaking without calculations or fear of anyone, and what is being said should be said to me.
“No one can say that Salah did not make a mistake by going to his brother's wedding at that difficult time and in light of the corona crisis, all the English newspapers speak against us negatively.
"Salah should have been blamed for what he did, but everyone feels fear.”
He is currently asymptomatic, but if he develops symptoms then he will be a doubt for the Champions League match against Atalanta and the league fixture against Brighton a few days later.