Over 100 people have been arrested after they were found to have been operating from Spanish airports, one of which was El Altet, or Alicante-Elche.
They mainly used Spain as the gateway to Europe and, once the Chinese migrants were within the Schengen zone, were able to head easily to France, Italy and the Republic of Ireland.
Others managed to get into the UK from Spain.
Those smuggled were Chinese nationals who wanted to get out of their country of origin, and paid a large sum of money – which varied according to their final destination and means of transport – which covered their flight tickets and fake passports and visas.
Some of the visas and passports were genuine, and had been stolen from third parties, but the forged ones were said to be of excellent quality and difficult to detect.
Once they arrived in Europe, they were kept in tiny, overcrowded flats with poor sanitation and no mains utilities.
This is thought to be one of the largest human-smuggling organisations broken up so far in Spain.