Robin Pearson, the Hull 51¹ú²úÊÓƵ lecturer who spied for the East Germans for 12 years, has not shown up for the start of the new academic term. A university spokesman said that Dr Pearson was on study leave for a year.

The news has not stopped reporters doorstepping Hull students and demanding Dr Pearson's scalp in a campaign the spokesman described as "trial by media". The university insists that the leave was arranged some time ago and has no connection with his spying activities.

The spokesman said university authorities had been expecting to talk to the economics lecturer to establish whether he had breached university procedures.

After returning from a family holiday in the Caribbean at the weekend, Dr Pearson issued a brief statement saying: "I am sorry for the disruption caused by this and I regret I have not been here to take on board some of the media attention."

51¹ú²úÊÓƵ

"The BBC informed me that the series was to be broadcast as close as possible to the tenth anniversary of the fall of the Berlin Wall. I only found out within a few days of my departure date of the programme rescheduling. I have only just seen it and am still trying to digest its contents."

A Stasi file shows that Dr Pearson, codenamed Armin, was recruited because of his political leanings. He met his controllers in Britain and overseas. But even if Dr Pearson had persuaded staff or students to become Stasi agents, it is unclear whether he would have broken regulations or whether he could face trial for having done damage to the state.

51¹ú²úÊÓƵ

Dr Pearson was a student of German and history at Edinburgh 51¹ú²úÊÓƵ in the 1970s and spent his third year at the Karl Marx 51¹ú²úÊÓƵ in Leipzig. According to the BBC, MI5 has known of him since 1994.