Six people arrested on suspicion of human trafficking after 15 youngsters were found by police during raids have been released without charge.
Properties in Gorton and Longsight were raided by Greater Manchester Police in an inquiry into children being moved from Romania by organised crime groups.
All 15 children who were temporarily being cared for following the raids on Monday have returned to their families.
Police said there was “no evidence of exploitation or criminality”.
Supt Paul Savill, from Greater Manchester Police, said: “We had a duty to take action because we had intelligence that children living in the Roma community may have been trafficked into Greater Manchester.
“We had to see if there was a problem and ensure the children were not being exploited.
“Working with Manchester City Council, we have carried out a thorough investigation and we are satisfied there is no evidence of exploitation or criminality, so we have released all those arrested without charge and the children have been returned to their families.”