Venel Joseph was killed Tuesday, the Miami Herald reported. The National Police said witnesses described two men on motorcycles who approached his van and opened fire, Haitian news media said.
Joseph's son, Patrick, 50, served as head of Haiti Teleco from 2001 to 2003. U.S. prosecutors in Miami say that telephone companies paid kickbacks to get low long-distance rates from the state-owned telephone company.
Aristide has not been charged. But the Herald reported Sunday that Patrick Joseph pleaded guilty last month to money-laundering in a deal that includes testifying against the former president.
Police in Haiti have not linked the elder Joseph's killing to his son's agreement.
"Regardless of who is responsible for this tragedy, a message has been sent," David Weinstein, a Miami lawyer who formerly headed the narcotics section in the U.S. attorney's office, told the Herald.
Aristide was ousted from office in 2004 and lived in South Africa for several years before returning to Haiti. Ira Kurzban, his Miami lawyer, described the investigation Saturday as part of a long-running "smear campaign" by the U.S. government.