The former Enron vice-president made the comments after addressing a London meeting of the Association of Certified Fraud Examiners.
It is up to institutional investors, who ultimately control most large corporations, to be more active in reining in rogue executives, she said.
“I do think that the imperial chief executive officer is not dead in America. You have a lot of CEOs acting more like dictators from resource-rich African countries treating their companies’ assets as their own.”
The corporate excess at companies such as Tyco seemed to show a culture where senior executives could not get enough personal reward from their companies, added Ms Watkins, who was made Time magazine’s person of the year in 2002 for highlighting wrongdoing at Enron.
She joined Enron in 1993, initially working for Andrew Fastow, who managed Enron’s $1bn-plus portfolio of energy investments. In August 2001 she alerted the then chief executive, Kenneth Lay, to accounting irregularities and resigned in November 2002.
Last night she described standing up against corporate excess as a “lonely road to take” and said she disliked the term whistleblower because it had a pejorative ring to it.
Other “corporate sentinels” were treated like pariahs – driven to divorce and alcoholism – and things would not change as long as bosses labelled as troublemakers those who warned of wrongdoing inside businesses.