US$40 million

Mickelson suffered gambling losses of $US40 million book reveals

Author Alan Shipnuck's upcoming Mickelson book was the source of controversial remarks Mickelson made about Saudi financiers backing a rival golf circuit.

Shipnuck has released another excerpt of the book on line saying the gambling losses were uncovered by auditors during an insider trading investigation that Mickelson was involved in 2016.

"Mickelson's love of gambling is fundamental to understanding his style of play as a golfer. It might also explain the Saudi seduction," Shipnuck wrote.