Candidates in the Miss Landmine beauty pageant, Sut Ai, left and Mom Sam Un, in Siem Reap, Cambodia. Photograph: David Longstreath/AP

A beauty pageant for victims of Cambodia's millions of landmines has been cancelled after the government denounced the event as an insult to disabled people.

Khieu Khanarith, a government spokesman, said today that the Miss Landmine contest, which was to have taken place this Friday, would "make a mockery of Cambodia's landmine victims. The government does not support this contest."

Twenty contestants aged 18 to 48 were due to appear in a photo exhibition in the capital, Phnom Penh, with members of the public invited to vote for their favourite over the internet.

The winner, due to be announced in December, was to receive a crown and a custom-made prosthetic limb.

Organisers of the event, held for the first time in Angola in 2007, said they had failed to persuade the Cambodian authorities to reverse their decision in last-ditch talks this morning.

"I am extremely disappointed with the government's decision," the pageant's Norwegian director, Morten Traavik, said. "I have tried to find a solution but we cannot reach an agreement."

Last week the country's ministry of social affairs warned the organisers that the event would damage "the dignity and honour of our disabled, especially women".

Traavik said he still hoped to proceed with the online vote, with the winner to be announced on New Year's Eve. Photographs of the contestants, all wearing crowns and evening wear, can be viewed on the pageant's website.

Traavik said the pageant was the victim of a misunderstanding by the Cambodian government, which had previously given it its blessing.

He said the contest was designed to raise awareness of the dangers posed by unexploded landmines and to enhance the participants' sense of self-worth.

Previous plans for beauty pageants have run into trouble in Cambodia, a country still coming to terms with its tragic past. In 2006 the country's prime minister, Hun Sen, cancelled a Miss Cambodia contest, saying he would not allow the event to go ahead until poverty had been more than halved.

The Cambodian countryside is littered with an estimated 4m to 6m landmines and other unexploded ordnance laid during the civil war. The weapons kill or injure hundreds of civilians every year.