It was the NSW opposition's idea to offer a reward for information on the person responsible for the Jennifer Franco hit and run last year, the Liberals have claimed.

The NSW government announced yesterday $100,000 would be offered for information leading to the arrest and conviction of the guilty party.

But shadow police minister Mike Gallacher said the Coalition called for a reward to be offered to help identify the driver involved on January 8, after the case against the man initially accused of the crime was dropped when it was established he could not have done it.

Mr Gallacher says it should not have taken three months for the government to act on the case.

"When the case against the man originally thought to have been responsible was dropped, Morris Iemma and David Campbell should have immediately ensured anyone with any information surrounding this case was given every reason to come forward," he said.

"Even if they couldn't manage to think of it for themselves - we suggested it at the time - why has it taken another three months for them to finally act?"

Mr Gallacher said offering rewards was a tried and tested measure to elicit information from 'otherwise unwilling participants' in the judicial process.

"Jenny Franco deserves every assistance to help her fully recover from the tragic and criminal act that almost cost her life," he said.

"Any measure that ensures the person who ran her down faces justice sooner rather than later must be pursued by this government."

Ms Franco was dragged 150 metres by a car on February 20 last year, costing her an eye.