While no criminal proceedings will be instigated, the investigation has concluded that the data breach was the result of a ‘sophisticated and carefully orchestrated attack on the CRU’s data files, carried out remotely via the internet’.

Norfolk Constabulary: Police closes UEA investigation

In other words – they have no indication that there was a hack, they have no idea who collected the files, but they do know that the zipped files were transmitted over the Internet by someone.

h/t to Marc Morano