The FBI is now in possession of threatening and harassing messages sent to Lindsay Lohan and other members of her family.

Lindsay has been receiving a variety of ominous messages … some of which her people believe came from Britney Spears’ ex BFF, Sam Lutfi.

Sources tell us Dina Lohan and Michael Jr. have also been receiving strange messages — some of which badmouth Dina, others warning them to stay away from Lutfi and Michael Lohan.

We’re told DiLo has passed along the info to the FBI — the agency that worked with her on Ali Lohan’s identity theft case — and they’re “looking into it.”
tmz