They were arrested yesterday by sheriff’s deputies, and prosecutors allege that Jason Rimmer, 36, of San Mateo, Ca., and Robert Troy Nipar, 43, of Simi Valley, Ca., suckered the biotech over a nearly two-year period starting in 2004. Each is charged with one count of grand theft and one count of criminal conspiracy, according to the Ventura County District Attorney’s Office.

Their scheme? Rimmer worked for Amgen at the time as an event planner, Shirley Hayton, a deputy district attorney, tells the Ventura County Star. He allegedly provided Nipar with a list of fictitious businesses with names that were strikingly similar to legitimate Amgen vendors.

Nipar then billed Amgen’s American Express account for nonexistent services and forward the false invoices to Rimmer, who then approved them for payment, prosecutors allege. Rimmer left Amgen in June 2006 for a job in Northern California, and shortly after his departure, Amgen’s accounting department became suspicious over some of the invoices approved by Rimmer.

Hayton said Amgen launched an internal investigation, then contacted sheriff’s investigators in August. Rimmer and Nipar were arrested, then released from County Jail on $20,000 bail, authorities said. They are scheduled to be arraigned Friday in Superior Court.

Hmm….And Richard Nanula resigned as cfo not long ago. Could there be….? Nah. What’s $300,000? Anyway, Kevin Sharer says things at Amgen are under control and there’s no crisis.