Diddy Prosecutors Need Gag Order to Block Potential Appeal, Deputy D.A. Explains

Mark Geragos may not like that Diddy's lawyers are subject to a gag order -- and so is he ... but, a prominent prosecutor from L.A. says prosecutors need it to avoid a possible appeal.

Kirsten Brown-Neil -- a deputy district attorney for L.A. County -- spoke with us on "TMZ Live" about Judge Arun Subramanian warning Geragos to watch what he says on our "2 Angry Men" podcast.

When asked about Geragos citing a Supreme Court ruling saying defendants and their attorneys have the right to speak publicly about the case, Kirsten said she thinks Geragos is taking a very narrow view of the ruling.

Kirsten says our very own Harvey Levin needs to watch what he says on the podcast too ... or, he and Geragos might end up being used as a grounds for appeal in this case!

As for whether it should be up to the defense to decide if they're talking too much to the public and potentially poisoning their case, Kirsten says it's actually unfair to the prosecutors ... 'cause someone like Geragos could end up sabotaging his own client on accident.

The way Brown-Neil explains it, if Geragos is some sort of unofficial member of Diddy's legal team -- something he's kept mum on so far -- then by speaking out and biasing the jury in some way, he himself could be used in an ineffectiveness of counsel appeal.

So, if prosecutors are able to secure a conviction, they don't want MG talking ... because Diddy's side could try to use something like that to appeal the decision.

Brown-Neil says prosecutors can't just secure a conviction -- they have to protect it once they get one too.

Kirsten also talks about how prosecutors are representing the public ... so, the public has the right to hear them discuss the case when they can.

Of course, prosecutors sent a letter to the judge about Geragos referring to them as a "6-Pack of White Women" on a recent episode of "2 Angry Men" -- and he told Geragos, "I'm going to be watching and I'm going to be listening. All right? You have one more listener for your podcast."

Day three of jury selection finished up Wednesday ... and, the 45-member jury pool has now been selected. While there's no court tomorrow, that number will be whittled down to 12 jurors and 6 alternates on Friday.