"They’ll be used at the right moment for our campaign, in Switzerland first and then worldwide," Mr de Roten says.
Tunick split the volunteers into two groups of about 300 for separate shots on or around the lower end of the spectacular 23 kilometre long sweeping ice floe, at an altitude of about 2,300 metres and about an hour’s hike away from the village of Bettmeralp.
Temperatures were well above freezing – about 10 to 15 degrees Celsius – unlike the riskier snowbound section higher up in the mountains.
The US-born photographer is renowned for his spectacular art photos of hundreds if not thousands of naked people grouped in carefully chosen poses around landmarks.
Tunick calls them "living sculptures" or "body landscapes" and these days he works mainly to order for contemporary galleries.
About 18,000 nudes posed for the US-born photographer in Mexico City’s Zocalo Square in May.
Other backdrops have included the Gateshead Centre for Contemporary Art in Britain (2005), the Biennale in Lyon, France (2005), and Grand Central Station in New York (2003).