AIADMK has not made any official statement on the expulsion and has neither confirmed the reports.
According to preliminary reports, Sasikala and her family yielded huge clout within the party and Jayalalithaa wanted to cut them to size and distance herself from the family. Jaya was apparently upset with top IAS officers reporting directly to Sasikala and family that led her to take such a drastic decision.
Jayalalithaa has instructed all members within the party to avoid any communication with Sasikala and her family.
There are also unconfirmed reports that Jayalalithaa took the extreme step after there were rumours that Sasikala might turn approver in the disproportionate assets case against Jayalalithaa.