It says in the article that the kids had passports but these have now been surrendered.They won’t have documents, certainly not to travel on. One report said the family dont have any status in the UK and I’d said before that Roma don’t tend to have passports as no country will recognise them as their own
I would think that one condition of their return to relatives would be the prior surrender of said passport (as reported) so that the stated plan for removal to another country is no longer possible.