Whose figures do we trust?

"650,000 New National Insurance Numbers for
EU Nationals Despite Official Figures Saying There
Are Only 260,000 Migrants"

The above headline, from Breitbart does not seem to have received any significant coverage from the major media sources, and certainly not from the BBC.

What does this mean? Does it mean that the immigration figures are wrong and some 650,000 new immigrants entered this country last year? Or does it mean that some are collecting two or three numbers, perhaps under different names, enabling them, presumably, to collect several lots of benefits.

Your guess is as good as mine, but I think that we deserve some official explanation.