International investigators see money transfers made through the U.S. companies as key clues in a globe-spanning manhunt aimed at identifying more than two dozen suspects in the case, according to officials familiar with the matter.

The U.S. companies identified by investigators include Internet-based businesses that match freelance job-seekers with employers and process payments between the two sides. Authorities have identified financial transfers from several of these intermediary businesses into prepaid, cash-card accounts used by suspects in the Dubai killing, according to international investigators.

U.S. authorities say they don't believe the intermediary companies had any way of knowing the money would be used in the plot, according to a U.S. official familiar with the investigation.

Instead, U.S. investigators believe, suspects might have posed as freelancers in order to get money in a way that obscured their funding source, and used the money for operational expenses, such as buying plane tickets.