As part of PRWeek's 'State of the Public Sector' investigations, it was revealed that the body set up to protect the public purse currently has 11 members of comms staff, down from a high of 50 in 2010.
The number is set to dwindle to one after the comms department officially closes on 31 March next year.
A spokesman for the Audit Commission said that the one member of staff remaining will represent a 'much smaller' commission as powers are transferred to private sector auditors.
He added that the declining staff numbers could also be attributed to the growing use of digital work.
Spending on comms has been severely wound down at the Audit Commission as the financial overseer moves towards closure, after it was accused of having 'lost its way' by Communities Secretary Eric Pickles.
Spending on PR has dropped from more than £540,000 in 2007-08 to a projected £190,000 in 2012-13.
The closure date of the body has been the subject of media speculation after it was originally planned for the end of 2012.