They haven’t begun their investigation into Assemblyman Vito Lopez yet, but officials in the Staten Island DA’s Office are already worried about leaks in their upcoming probe, The Post has learned.

“This is obviously extremely politically charged,” said a source familiar with the matter. “It just leaves it wide open for people to say its a witch hunt.”

Leaked details of the investigation could be seen as a political attack against him.

Lopez resigned as head of the Brooklyn Democratic Party amid accusations that he sexually harassed several female staffers.

Daniel Donovan, the Staten Island DA, is a Republican and was assigned the case because the Brooklyn DA, Charles Hynes, a Democrat, has political ties to the assemblyman.

Donovan plans to begin selecting prosecutors and probers early next week to kick off the case against Lopez.

“You have to gather everything from the beginning. Who the hell knows where this can go, or what a complete, sprawling mess this can be?” the source said.