Hepatitis C Trust chief executive Charles Gore told its Improving Hepatitis C Healthcare conference in Birmingham that around 200,000 people in England are chronically infected with hepatitis C, but only 38,000 diagnosed.
An audit by the all-party parliamentary hepatology group last year showed that PCTs, strategic health authorities and hospital trusts were having problems implementing the Department of Health's action plan.
The 2004 plan called on PCTs to improve services to enable better detection and treatment of the disease.
National Institute for Health and Clinical Excellence head of communications Louise Fish said the cost of treating mild hepatitis C would increase to around£70m in five years, and that no additional money was being made available by the government.
The cost of treating moderate to severe hepatitis C is estimated to be around£10.2m a year.
'NICE believes there could be cost savings in the longer term if the action plan is implemented by PCTs - the DoH says PCTs should be putting it into practice and that if doctors feel the drugs would benefit patients, the money should be made available,' said Ms Fish. If left untreated, hepatitis C can cause serious liver disease.
A PCT manager from the midlands said: 'We're looking at a problem that is quite large and requires either taking money out of something else or finding some genuine new money.