The Christmas party for the top bureaucrats in Victoria's Education Department was renowned as the one to attend, and was perhaps the most extravagant in the public service.

Buses were hired to take staff to an inner-city bowling green, the booze was top shelf and free flowing, and all invitees left with a well-stocked gift bag.

But this end-of-year celebration was not an isolated event. With Victoria's anti-corruption agency continuing its probe of the Education Department, evidence is emerging of a hedonistic culture enjoyed by some of its most senior bureaucrats between 2004 and 2011.

Fairfax Media has seen two confidential 2011 audits of credit card and purchase card expenditure within the department that identified several "high-risk" incidents and breaches of government spending policies.