Detectives stormed eight addresses across the county yesterday and on Tuesday as part of Operation Pentameter 2 –– a national operation involving police, the UK Human Trafficking Centre (UKHTC) and other law enforcement agencies

All 16 of the people arrested were foreign nationals from China and South East Asia and were arrested in relation to prostitution or people trafficking –– and 12 of them have now been released on bail pending further inquiries.

No victims of trafficking have been identified or rescued from the addresses –– although a number of potential immigration offences are being investigated by officers from the Foreign National Crime Unit.

The operation follows the success of Operation Pentameter 1, which took place in 2006 and saw 55 forces across the UK work together to make more than 230 arrests and recover 88 victims of trafficking from 22 different countries.

Det Insp Ian Winton, head of Nottinghamshire Police's Sexual Exploitation Investigation Unit, said the operation had been a multi-agency effort also involving officers from the force's City Kerb Crawling Task Force, the newly formed Foreign National Crime Unit, and police colleagues from Derbyshire and Lincolnshire.

"We may not have found any trafficked victims in the course of these raids, but we are under no illusion that this is a problem across the East Midlands," he said.

"The victims of human trafficking are also victims of coercion, exploitation, deception, kidnap, false imprisonment and rape. They are victims of serious and organised crime, with huge profits being made by those at local, national and international levels."

Police are asking anyone with information about prostitution or trafficking to come forward and help the operation, including victims of trafficking, stressing that Operation Pentameter 2 has a focus on the victims of crime and the services available to them.

Anyone with information should contact the police's Sexual Exploitation Investigation Unit on 0115 9482999 ext. 4095 or call Crimestoppers anonymously on 0800 555111.