Police have been granted another 36 hours to question three people arrested as part of an inquiry into child abuse allegedly committed by a female nursery worker.
Vanessa George, 39, who worked at Little Ted's nursery in Plymouth, Devon, has already been charged with sexual assault and making and distributing indecent images of children.
Officers in Nottingham on Wednesday arrested another woman, also 39, a 21-year-old man and a 17-year-old boy.
The woman was arrested on suspicion of possessing indecent images of a child, indecent assault of a child and conspiracy to rape a child, said Nottinghamshire Police.
The man and teenager were held on suspicion of possessing indecent images of a child and suspicion of raping a child, the force said.
Magistrates in Nottingham on Thursday granted police a 36-hour custody extension, which will allow officers to question the suspects until 9am on Saturday.
Nottinghamshire Police said the arrests came after information was received from their counterparts in Greater Manchester late on Tuesday night.
Officers were granted a search warrant before carrying out the raid, police added.
