Criminals stole the Facebook identity of Interpol head Ronald K Noble and used it to obtain information on an operation by the international police agency, Noble said.
"Just recently Interpol's Information Security Incident Response Team discovered two Facebook profiles attempting to assume my identity as Interpol's secretary general," Noble told the first Interpol Information Security Conference in Hong Kong.
"One of the impersonators was using this profile to obtain information on fugitives targeted during our recent Operation Infra Red."
The operation brought together investigators from 29 member countries to target criminals on the run from justice for crimes including murder, paedophilia, drug trafficking and money laundering, Interpol's website said.
It led to more than 130 arrests, Noble said.
"This is why we constantly need to share our experience," he added at Wednesday's opening ceremony of the conference.
Almost two thirds of all adult web users globally have fallen victim to some sort of cybercrime, according to the 2011 Norton Cybercrime Report.