A former student donated the Demerara Bell to St Catharine's College in Cambridge in 1960.Read more
The Gangmaster's Authority has arrested a second man over allegations a 58-year-old man was kept in a small shed and exploited for 40 years at a residential site near Carlisle.
Officers from the Gangmasters and Labour Abuse Authority and Cumbria Police said a 79-year-old man arrested last autumn had been released under investigation.
A 53-year-old man has now been arrested on suspicion of similar offences.
Officials have renewed an appeal for information about the case.
Fifty six victims of modern day slavery have been helped by a Birmingham charity in two years.
Sifa Fireside in Birmingham said it's shocked at the increasing numbers of vulnerable people forced to work for a pittance.
The charity's calling for more resources to tackle the problem.
Chief executive Carly Jones said "several victims" are presenting themselves on a daily basis.
"Our figures are just the tip of the iceberg," she added.