Giuliani's enterprises have put him in league with corporations that, decades ago, he might have faced in court. An example: Naturex Inc., a French food-flavoring firm that hired Giuliani Capital Advisors to help with its 2005 acquisition of another company.

A year later, Naturex was sued by the U.S. attorney in New York — a job Giuliani once held — for violating the Controlled Substances Act. A Drug Enforcement Administration inquiry concluded Naturex had imported and exported benzaldehyde — a chemical that can be used in amphetamines and methamphetamines — more than 100 times without telling the government. In 2004, Giuliani was hired by the pharmaceutical industry to study — and testified before Congress on — the dangers of importing prescription drugs.

A spokeswoman for Giuliani Capital Advisors said Monday the firm was unaware of any inquiry by the DEA into Naturex's business at the time.

Naturex paid $325,000 to settle its case. A company spokeswoman and attorney did not respond to requests for comment.