It's not often that Pierce Brosnan makes headlines for negative reasons, but the Irish actor has fallen foul of the law after a photo of him allegedly trespassing went viral.

The Navan man was spotted in a photo posted by the Instagram account @touronsofyellowstone, which re-posts critical photos of tourists seemingly doing unwise or forbidden things in the park.

The 70-year-old Brosnan was spotted standing on the terraces of the Mammoth Hot Springs, near the Wyoming/Montana border, but tourists are not permitted to step off the boardwalk. Given how important and delicate the ecosystem of the vast park is, it is an offence to step out out the boundaries and trespassers can be fined, banned or even jailed for doing so.

It can take years to correct damage inflicted on the area and the hot springs area is also dangerous, given the high temperature of the acidic water - with people being badly burned or even losing their lives in the past.

The James Bond actor was actually charged with trespassing last month, but has not pleaded not guilty to the charge. A hearing is scheduled for February 20th.

The park attracts millions of visitors each year, but it's believed that at least 22 people have died over the years, from burns sustained from hot springs and geysers.

Although it was initially believed that Brosnan was shooting a film in the area, he was reportedly in the park for pleasure, rather than business.