Control Plus, the parking enforcement company, is receiving an extra payment for every parking ticket given to motorists in Oxford.

The company has always insisted it has no financial incentive to be overzealous.

But after using the Freedom of Information Act to view County Hall's contract with the parking firm, the Oxford Mail can reveal that an additional payment -- about £2 -- goes to Control Plus for every £20 parking penalty notice.

With an estimated 55,000 tickets a year given to motorists in the city, the annual payments easily exceed £100,000.

The county council says the payments are to cover the administrative cost of processing every penalty charge notice correctly. Both County Hall and Control Plus have rejected suggestions that it amounts to a hidden productivity bonus.

The county council says it fails to break even, after paying Control Plus £1.5m a year.

The contract, running for another two years, shows that Control Plus receives fixed and bonus payments.

County Hall declined to allow us to print the exact figures, because of any potential commercial disadvantage that Control Plus might incur.

But payment in the region of £2 applies to penalties paid within 14 days. If a notice of debt registration is issued, additional payments rise rapidly to about £8. A payment in excess of £10 goes to the company in cases where bailiffs are involved.

Graham Jones, spokesman for Rescue Oxford (ROX), said: "Control Plus have some good people who show discretion. But some attendants seem to have it in for the poor old motorist and are just waiting to pounce."

Control Plus is owned by Central Parking System, a subsidiary of the Central Parking Corporation in the US. A spokesman for Central Parking System said: "None of Control Plus or Central Parking System's staff receives bonuses linked to Penalty Charge Notice issue levels.

"Neither do they receive incentive offers, such as holidays or vouchers."