Forty other documents may be missing
Documents containing payroll information relating to 182 NHS staff members have been have been found dumped in a street.
They contained information, including addresses, bank account and National Insurance details, from five trusts in Leicestershire and Northamptonshire.
Police were informed and collected the documents after they had been found in a street in Stevenage, Hertfordshire.
The documents had been in the care of company Capita when they were lost.
It is understood the papers were found in a residential street by a member of the public on 21 March.
They included details of employees at Leicestershire Partnership NHS Trust, University Hospitals of Leicester NHS Trust, Leicester City Primary Care Trust, Leicestershire County Primary Care Trust and Northamptonshire Healthcare NHS Trust.
Forty more pieces of information which may have been left with the found papers are unaccounted for.
Capita, which runs the payroll service for the five trusts, and the Trusts have launched investigations into what happened.
All of the affected employees have been contacted.
Trust consortium Kathy Renacre, said: "We demand that the highest possible standard of care is taken with all employee personal data. Any breach of those standards is completely unacceptable.
"We will get to the bottom of what has happened and make sure that it can never happen again."
A Capita spokeswoman said: "Capita Group have an excellent track record in terms of data security - both its storage and disposal - and take any breach of procedures very seriously."