It's been reported that the information was mistakenly posted online by the force itself in what's been described as supposed 'human error'.
"This level of data breach is clearly of profound concern, not least to police officers, civilian staff, and their families, who will be feeling incredibly vulnerable and exposed tonight and in the days ahead," said Mrs Long.
"Immediate action must be taken to offer them proper information, support, guidance and necessary reassurances regarding their and their families' security.
"Whilst the personal data has now been removed, once such information has been published online, it leaves an indelible footprint.
"That such sensitive information could ever have been held in a manner open to such a breach is unconscionable and will require serious investigation; however, the most urgent issue is supporting those whose security has been compromised.
"Alliance representatives on the Policing Board are seeking an urgent meeting of the Board to be convened with PSNI Senior Management Team to address this unprecedented security breach."