Two men from Australia are suing the Federal Government after they were attacked by a grizzly 15 years ago in Lake Louise.

Owen Hereford and Andrew Brodie were two of six tourists severely injured when they were mauled by a grizzly at a Lake Louise campground in Banff National Park.

The mauling happened at 3:30 in the morning on September 29th 1995 and at the time, even authorities were shocked by the unprovoked attack.

The lawsuit claims federal officials were negligent by not doing enough to keep campers safe from roaming wildlife, even though signs were posted warning of a bear in the area.

The men are seeking $75,000 each in damages and are also after compensation for loss of past and future income. An economist testified for the plaintiffs in court on Wednesday and suggested that amount could be as high as $2 million.

A statement of claim says both men continue to suffer from extensive mental and emotional distress and have ongoing disabilities as a result of the attack.

The pair and their lawyer won't comment until after the case wraps up.

A bear expert is expected to take the stand on Thursday and park wardens and conservation officers will testify next week.