Thiago Silva was sent off by Castro in the 43rd minute at the Parc des Princes after placing his hands on the official's chest, a decision which drew the ire of Leonardo, who appeared to deliberately shoulder-barge Castro in the tunnel after the match.
"The [French Football League's disciplinary] committee, following further reports from the referee and (match) delegate, puts the case under investigation and suspends Leonardo from Wednesday May 8th until further notice owing to the seriousness of the facts," read an LFP statement, without specifying when a final decision would be made.
Leonardo denied the allegations on Monday, telling AFP he had been pushed into Castro.
"I wanted to speak to the official and I waited for him. There were lots of people returning to the changing rooms and when Mr. Castro arrived there was a delegate in front of me trying to block me who pushed me," explained the Brazilian.
"I then, with my back, made contact with the referee. It's hard to see in the footage but in slow motion you can see it."
During the ban Leonardo will be barred from both the touchline and changing room as well as performing any official club duties.
As for Silva, the defender will miss Sunday's fixture at Lyon and the visit of Brest the following week, leaving him available to return for the season finale against Lorient on May 26th.