An investigation into allegations that Sheffield Hallam University faced sustained pressure from China to shut down human rights research has been referred to counter-terrorism police.

The BBC and the Guardian newspaper has been reporting that documents show that China had waged a two-year campaign of intimidation and harassment, including demands the university stop sensitive research by one of its professors into claims of forced labour in the Xinjiang region of China.

A South Yorkshire Police spokesperson said the force has referred the investigation on because the "allegations fall under Section 3 of the National Security Act".

Section 3 of the act deals with "assisting a foreign intelligence service".

An offence is committed if someone behaves in a way that "intends that conduct to materially assist a foreign intelligence service in carrying out UK-related activities," or in conduct likely to assist that service.