Department of Conservation (DOC) rangers admit being powerless to stop tourists risking their lives by getting close to the Franz Josef and Fox Glaciers.

Visitors are ignoring warning signs and breaking through safety barriers to get closer to the glaciers.

In February, two men were injured, one seriously, when they ventured into an unstable ice cave at the face of the Franz Josef Glacier and were hit by ice falling from the cave's roof.

As the summer visitor season begins, rangers are appealing to tourists to pay attention to the warning signs. DOC's Franz Josef visitor assets manager Dave Waters said the problem was as bad as it was last summer.

An internal assessment report of the hazards in the valley had been completed.

"Rangers speak to everyone they see beyond the barrier and explain the reasons for this," Waters said. "Due to current legislation, the signs (and) warnings can only be a recommendation – we can't restrict access in the (Westland) National Park.

"The signs with symbols should cater to non-English speaking people and we are trying to determine why they are still being ignored."

A few days ago Australian visitor David Worwood photographed a German-speaking tourist who entered a roped-off section close to the face of the glacier.

"Several other tourists ignored the warnings and did likewise," Worwood said. "It seems more than likely that this person did understand the sign and just decided to ignore it."