Dr Alan Billings spoke out after the Home Office announced a one per cent pay rise for bobbies along with a one per cent one-year lump sum bonus - ending a public sector pay cap which has limited pay rises for the past seven years.
He said he was pleased that police officers are to receive pay increases again but pointed out that no extra cash has been given to forces to meet the cost, meaning reserves will have to be used.
Dr Billings said: "I am pleased that police and prison officers in South Yorkshire will receive pay increases.
“But the government's announcement that police officers are to receive a pay rise of one per cent plus a 'bonus' of one per cent has two stings in the tail.
"First, the pay rises are wiped out by the increase in the cost of living that was announced on the same day.
“Second, no new money is being given to cover the cost, therefore Police and Crime Commissioners will have to find the money from within existing budgets. That means the
reserves will have to be used.
"This is a potentially dangerous path since reserves are kept for a reason. In South Yorkshire's case they are there in part to cover costs that arise from both the Hillsborough disaster and child sexual exploitation in Rotherham.
"Considerable sums of money are involved and the reserves are there in part to pay for them."