A former police officer is now assisting with investigations into last Wednesday's airport robbery.
The man was detained on Saturday night by officers of the organised crime and intelligence unit.
Last Wednesday, armed bandits escaped with an estimated $5 million in cash from the cargo cart at the tarmac of Piarco international airport.
Police said the man and two other women were being questioned up to late yesterday evening.
Last week, seven people were questioned soon after the incident.