Something stinks in Wade Robson's new molestation accusations against Michael Jackson -- so says MJ's famed trial attorney Tom Mesereau, who tells us the smell leads all the way back to AEG ... the company currently being sued by Katherine Jackson.

Tom called in to "TMZ Live" claiming the timing of Wade's accusations is extremely suspicious -- considering the legal battle currently raging between Katherine and AEG ... the concert promoters behind MJ's 2009 "This Is It Tour."

Katherine and Michael's children are suing AEG, claiming the company is responsible for MJ's death by negligently hiring Conrad Murray to care for the singer ... and potentially BILLIONS of dollars are at stake.

Mesereau insinuates Wade's accusations are motivated by money ... specifically a payoff from AEG, which is currently on a mission to trash Michael's reputation.

We reached out to AEG for comment -- so far no word back.