The number of vehicles found to be travelling on marked mineral oil or “green diesel” has continued its notable rise in recent weeks - while there has also been a spike in the number of cars travelling with defective tyres.

This comes as multiagency checkpoints test various vehicles on Irish roads.

According to members of An Garda Síochána, one car was stopped in Co. Kilkenny yesterday (Thursday, July 7) where offences were quickly discovered.

Taking to social media, Gardaí based in Co. Kilkenny said:

"Always think road safety," the Garda statement said.

Meanwhile, similar issues were brought to light at a multiagency checkpoint in Co. Wicklow yesterday, as noted by Gardaí on Twitter.

"Baltinglass Roads Policing Unit conducted checkpoints recently with the RSA and the Wicklow County Council Waste Enforcement and Customs," the tweet said.

"A number of detections were made; including a vehicle that was using green diesel and another that needed a replacement tyre," the Garda tweet added.

Finally, in Co. Laois on Wednesday (July 6) more tyre issues were uncovered.

In a separate tweet, local Gardaí said: "Laois Roads Policing Unit detected this car travelling at 189kph on the M7.

"They were arrested. Proceedings to follow," the tweet concluded.

According to the Irish Revenue, green diesel, also known as marked gas oil (MGO), is diesel on which mineral oil tax at a reduced rate has been paid on condition that it is used only for purposes that qualify for that reduced rate, such as agriculture.

It is chemically marked and dyed green to deter misuse for purposes to which a higher rate of tax applies.

It is illegal to use marked gas oil or marked kerosene in road vehicles, the authority notes.

Meanwhile, the Road Safety Authority advises that tyres must: be the right kind and size for your vehicle; be properly inflated; be free from defects; and have a thread depth of at least 1.6mm.