The law has been changed in Wales to make it easier to prosecute farmers who damage a scheduled monument on their land.

The Historic Environment (Wales) Act, which came into force on 21 March, simplifies the scheduled monument consent procedure, which was based on the Ancient Monuments and Archaeological Areas Act 1979.

The Welsh government said the law would make it easier for landowners to carry out small-scale works of maintenance and repair that had been agreed in advance with the Historic Environment Service (Cadw) after a site visit by an official.

See also: Tougher penalties for health and safety breaches

However, landowners also needed to be aware that the act would make it more difficult for individuals who damaged protected monuments to escape prosecution by pleading ignorance of a monument’s status or location.

It follows a case in 2014 where a man escaped being prosecuted for digging up a stretch of the 1,200-year-old Offa’s Dyke because he said he did not know it existed.

Under the new rules, landowners will have to be able to show all reasonable steps had been taken to find out if a scheduled monument would be harmed or destroyed by their actions.

Cadw will shortly launch a website which will provide details of the status, location and extent of all scheduled monuments.

If an ancient monument is at immediate risk of damage or destruction, ministers will also be able to authorise archaeological excavations without the owner’s consent.

This new power will only be used in exceptional cases where it is necessary to rescue valuable information about Welsh history.

There were 119 cases of damage to scheduled monuments in Wales recorded between 2006–2012, but only one successful prosecution.

Damaging a scheduled monument can result in a fine or a jail sentence of up to two years.