KPMG was forced to resign as auditor forHerbalife and Skechers, both companies announced on Tuesday after a senior partner named Scott London was discovered to be at the center of an insider trading probe and was fired by the accounting firm, a source familiar with the matter told CNBC.

In separate statements, Herbalife and Skechers acknowledged that KPMG had resigned as their auditor. The shares of both companies were halted during early trading, with speculation rife about the nature of the move.