Dr Joseph Crawford was found to have a total of 212,463 indecent images of children and 547 videos, nine of which showed the rape of underage victims.

Police Scotland raided his Falkirk home after he was traced through an investigation into a cyber-network of paedophiles sharing child pornography.

Officers seized devices and computers and forensic examinations uncovered the sickening material.

Last week, Crawford, 49, was sentenced to 10 months in prison and placed on the sex offenders’ register after pleading guilty at Falkirk Sheriff Court.

Crawford, a doctor of philosophy, was previously a respected member of the school of geography and sustainable development at St Andrews University and has contributed to books and written a number of papers on exploitation in housing.

He transferred to Sheffield University last year but continued to travel back to his home in Scotland.