An Armenian-led ring of 73 criminals has been arrested in the US for allegedly using non-existent clinics and identity theft to file fraudulent claims, bilking the US government medical insurance programme Medicare out of $163m.

The network's operations represent the largest Medicare fraud by one criminal organisation in history.

Federal prosecutors have brought charges against them, most of whom were capture during raids Wednesday morning in New York City and Los Angeles.

Roger Wilkinson reports.