The FBI announced Friday they have charged and arrested Galleon Group founder Raj Rajaratnam and five others in connection with a $20 million insider-trading case.

Rajaratnam was charged with four counts of conspiracy and eight counts of securities fraud.

This case represents the largest hedge fund insider-trading case ever charged criminally, U.S. Attorney Preet Bharara said Friday at a press conference.

 Galleon was shocked to learn today that Raj Rajaratnam was arrested this morning at his apartment. We had no knowledge of the investigation before it was made public and we intend to cooperate fully with the relevant authorities. Galleon continues to operate and is highly liquid, Galleon said in a statement.