Babcock Naval Services, which provides support services to the Ministry of Defence, is said to have removed the information – which detailed staff illnesses and the expiry dates of their sick lines – the day after it was posted.
An e-mail that listed the names of those on sick leave, the length of the time taken off and details of doctor's sick notes, was also forwarded to employees, according to the report.
Babcock has admitted the mistake, says icDunbartonshire, but some employees are considering making a formal complaint.
Emma Grossmith, an employment law specialist with Pinsent Masons, the legal firm behind OUT-LAW, said:
"Depending on the type of disclosures which have been made, this type of blunder could be severe enough to undermine the relationship of trust and confidence and give rise to a constructive and unfair dismissal claim."
William Malcolm, a privacy speciality with Pinsent Masons, added:
"This underlines the need for companies and public sector organisations investing in HR systems to ensure that they have appropriate procedures in place and that staff are properly trained in data protection."