A further 15 people have come forward after a report outlined claims of historical abuse by a doctor.
The number of people to speak to investigators about alleged abuse at Aston Hall psychiatric hospital has now risen to 130, Derbyshire Police said.
A report found children were allegedly given a “truth drug”, stripped, abused and put in straitjackets.
Police said Dr Kenneth Milner would have been questioned over rape and cruelty claims if he was still alive.
The vast majority of the allegations were made against Dr Milner, who ran the hospital from 1947 to the 1970s and died in 1975.
A Derbyshire Police report said there was “sufficient evidence to justify interviewing Dr Milner” over potential offences including rape, indecent assault, child cruelty and assault.
Other staff members accused of physical abuse have either been eliminated from the inquiry, died or were unable to be identified.
In the report, officers recorded 73 crimes, including 33 instances of physical abuse and 40 sexual offences, with lawyers saying the “horrific treatment” had “undoubtedly caused permanent damaging effects”.
The additional 15 people to come forward are a mixture of former Aston Hall patients and staff who were at the hospital between the 1950s and 1970s.
Det Ch Supt Kem Mehmet encouraged anyone who suffered abuse at Aston Hall or who worked there to contact Derbyshire Police.
“I am pleased that people have felt confident enough to contact our investigation team following the publication of these findings,” he said.