Car tax evasion in Northern Ireland has cost the exchequer £13m over the last year.
New figures from the Department of the Environment show that more than one in 10 motorists do not pay.
The figure, which has risen by £1m since figures were last published in September 2001, is twice the UK average.
Chief Executive of the Driver and Vehicle Licensing Authority Brendan Magee said more action was planned to catch people who did not pay their tax.
"Clearly the message here has to be that we have to intensify enforcement action," he said.
"We will do that by increasing our wheel clamping team, the camera technology and the number of special exercises that we undertake jointly with the police.
"We have one camera unit in use at the moment but that is supplemented by additional camera teams brought in from Great Britain and with that we have detected nearly 7,000 offenders.
"The cameras are deployed right across Northern Ireland."