Academics have called for an independent investigation into the Jason Arday affair that incorporates all universities implicated in the case amid doubts over how effective the University of Cambridge’s own probe will be.

Cambridge has announced it will launch a new investigation into its former star sociology professor after weeks of allegations of plagiarism and fabrication. Arday, who has denied the claims, resigned from his post on 5 August following the announcement, saying the public scrutiny had become unbearable.

It is far from clear what Cambridge will be investigating, however. The initial plagiarism allegations against Arday surround his PhD thesis, which was awarded by Liverpool John Moores University. This institution has already investigated and found the academic had no case to answer.

On 2 August, Cambridge stated that standard practices mean “investigations are carried out by the institution at which the research was undertaken”. Some three days later, it confirmed it would go ahead with an inquiry following “new information about Professor Arday’s academic qualifications and honorary appointments”.

“It’s not easy to see what Cambridge can properly investigate now,” said Robert Dingwall, emeritus professor of sociology at Nottingham Trent University. “Once [a] university has awarded a PhD, it’s not really up to another university to come in and say, ‘we want to dig behind that’.”