Officers are looking into claims that residents were abused by staff at the council-run Beechwood Children's Home in Mapperley which closed down in 2006.
Nottinghamshire Police say as part of their investigation into allegations of abuse at Beechwood Children's Home in Mapperley in Nottinghamshire they are also looking at similar homes.
Those under investigation are Bracken House in Bulwell, Ranskill Gardens in Bestwood, and Wood Nook in Beechdale.Officers are also looking at claims relating to Risley Hall in Derbyshire.
– Detective Inspector Yvonne Dales, Nottinghamshire Police
This is a thorough but complicated and sensitive investigation and the allegations are historic which in some cases relate to events which are said to have taken place nearly 30 years ago.
"We have experienced officers on the investigation team who are working hard on this case which presents many challenges, such as the difficulties around obtaining forensic and corroborative evidence, along with the fact that some of the alleged perpetrators have since died."
Police are investigating more than 50 allegations of physical or sexual abuse at a former children's home.
Nottinghamshire Police said they are investigating claims that people were abused at the council-run Beechwood Children's Home in Mapperley, Nottinghamshire.
In 2011 six alleged victims came forward saying they had suffered abuse at Beechwood.