Suffolk Police have said no action will be taken after concluding an investigation into allegations of inappropriate behaviour by staff at Old Buckenham Hall School, in Brettenham.Officers were called in to investigate claims at the boarding school in February.
It came after concerns were raised in an Ofsted welfare inspection.
Two staff were suspended during the investigation, which was carried out jointly between police and Social Services.
Police last month said no further action would be taken against one of the staff and today police issued a further statement saying the investigation had now concluded and no police action would be taken.
"Following extensive inquires into allegations of inappropriate behaviour by members of staff at a school in West Suffolk, Suffolk Constabulary can confirm that its investigation has concluded and no police action will be taken.