After the footage was released in September, Estonia, Finland and Sweden said they would conduct a joint investigation led by Estonia, the ship's flag state.
Estonia, Sweden and Finland want to find out how a large and long-unknown hole in the hull, which footage by documentary film-makers revealed last year, was created.
The process was initially due to start in November but was delayed after the authorities blocked two Chinese tech firms - Huawei and ZTE - from supplying equipment for the new infrastructure.