"There was just nothing there. No compassion, no joy, no life. These people kill for next to nothing without a second thought."

Mr Willmore's so-called "thin green line" of national park rangers became even thinner on the day he arrived in the Congo to deliver emergency aid.

Ranger Buzara had been tortured and murdered by anti-government rebels.

Days later, Mr Willmore's Mornington Peninsula-based campaign to support families of rangers who die protecting wildlife almost ended the same way.

Travelling with his friend Brett Vogel of Mornington, Mr Willmore said they received a tip-off that rebels were planning an ambush.

"We narrowly avoided an ambush with five rebels armed with AK47s because a fisherman warned us 200 metres from the ambush point. We backtracked for one hour and returned with 15 armed rangers and made it through. Two weeks later, at that same point, 50 rebels shot into the rangers' vehicle, killing a ranger's wife and daughter and injuring three others. These were people we had worked and shared meals with.

"Both of us had to pretend to be priests to get through rebel areas, which is funny for anyone who knows us.

"We went into rebel areas where other non-locals don't go, as this is where we had to assist rangers and their families. We were with expert guides, being the rangers, and had military support for parts of our journey."

Mr Willmore quit his job as head ranger of Warringine Reserve in Hastings and mortgaged his house to spend much of 2004 and early 2005 filming wildlife rangers throughout the world for his documentary The Thin Green Line.

The film graphically highlights the dangers rangers faced trying to protect wild animals, mainly from poachers.

Since its world premiere on July 31, 2007, sales and screenings of The Thin Green Line have raised $150,000 for the families of rangers killed in the line of duty.