Reports say Sydney motorists may have been unfairly charged nearly $1.5 million in tolls on the Sydney Harbour Bridge, but the Government cannot tell.

The NSW Government is reviewing whether faulty equipment led to extra fees being charged on more than 2.6 million trips.

It comes after reports that since June 2013, a 55-cent video processing fee has been charged if the automatic reader fails to read an E-tag.

Many say that the extra fee is not fair.

Minister for Roads, Maritime and Freight Duncan Gay says as far he knows, there is no problem, but the Government is investigating anyway.

“I was continuing to get assurances that everything was alright, yet I was getting a persistent number of people contacting my office and I think it's fair that we make sure that this equipment is operating properly,” he said.

“That's why about two months ago I put in place an independent, outside inquiry into the tolling on the Harbour Bridge to make sure that it was okay and it was being fair to our customers.

“The review is still underway, and as soon as we get any results, we'll certainly act on it.”

Opposition roads spokesperson Jodi McKay says she is not surprised people wonder if they are being charged correctly.

“The Government has to give an absolute guarantee that the system is working the way it should,” she said.

“You can't have a system where it depends on the lane you are driving in whether you are going to get pinged with an extra charge because camera equipment may be faulty.”