That is clearly illegal. Once in Spain, these people have the right to an asylum procedure by law.
One of the Guardia Civil cut the rope, the man fell to the Spanish ground from a height of four or five metres and was then deported to Morocco. This is also clearly against the law.
It all happened in front of dozens of witnesses. I wasn't there myself, but I was able to see four migrants in the CETI who managed to get through.
Addendum: all videos on the scandalous behaviour of the Guardia Civil are posted in the following blog posts, see: here and here.
The statement of the European Commissioner for Human Rights can be found here
Please keep posting this article, this brutal behaviour must come to an end.