KPMG has had to resign as auditor to two US companies after accusing one of its former partners of passing confidential information about its clients to an alleged insider trader.

Los Angeles-based Herbalife, the maker of nutritional supplements at the centre of a battle between corporate raider Carl Icahn and short- seller Bill Ackman, said it was one of the two companies that now had no auditor.

Footwear maker Skechers said it was the other.

The US attorney’s office in Los Angeles and the Federal Bureau of Investigation are investigating the alleged passing of confidential client information.

The US arm of KPMG said its independence was compromised by a partner in charge of its practice in Los Angeles until very recently. The person was fired immediately after KPMG was informed of the matter late last week, the accountant said. – Copyright The Financial Times Limited 2013