They, however, said the train moved at a restricted speed.
The corridor, commuter service on which was suspended in July following identification of major faults in the civil structure, was yet to get a safety certificate, mandatory to carrying passengers.
RK Kardam, commissioner of metro rail safety (CMRS), said: "I do not know how the actors were allowed to commute in a train before the line was inspected."
According to Sudhir Krishna, secretary, ministry of urban development, repair works on the 22.7km corridor is complete and the line is awaiting a safety inspection. "The line will open after the CMRS gives his nod for commercial operations," he said.