HP chairwoman Patricia Dunn has been forced to step down after the company admitted to several cases of identity theft. 

Dunn is scheduled to step down as chairman of the board of directors in January 2007 and will be succeeded by current chief executive Mark Hurd.

HP became the centre of a controversy last week when it revealed that a private investigator had committed identity theft to find the source of confidential information leaks within HP's board.

The investigator had obtained phone records from reporters and board members by posing as the account holder.

"Unfortunately, the investigation, which was conducted with third parties, included certain inappropriate techniques," said Dunn in a statement.

"These went beyond what we understood them to be, and I apologise that they were employed."

Hurd added: "I am taking actions to ensure that inappropriate investigative techniques will not be employed again. They have no place in HP."

US authorities and the Securities and Exchange Commission have launched investigations into the matter.

The private investigator pointed to HP board member George A. Keyworth II as the alleged source of the data leaks.

Keyworth was asked to resign in May, but declined. Another board member, Thomas J. Perkins, resigned over a dispute with Dunn over the investigation.