A boy watches as a United Nations truck is loaded with humanitatian aid January 23, 2010 in Leogane, Haiti. The United Nations formally rejected a multi-billion-dollar damages claim for a cholera epidemic in Haiti that has been widely blamed on UN peacekeepers

The United Nations formally rejected a multi-billion-dollar damages claim for a cholera epidemic in Haiti that has been widely blamed on UN peacekeepers.

About 8,000 people have died in the epidemic since October 2010 but UN spokesman Martin Nesirky said a complaint made by lawyers for the victims was "non-receivable" under a 1946 convention setting out the UN's immunities for its actions.

UN Secretary General Ban Ki-moon telephoned Haiti's President Michel Martelly "to inform him of the decision and to reiterate the commitment of the United Nations to the elimination of cholera in Haiti," Nesirky said.

Lawyers for thousands of the victims rejected the UN statement and said they now plan to file a case with a court in Haiti, the United States or in Europe.

Some health experts say the cholera epidemic was introduced to Haiti by Nepalese peacekeepers.

More than 635,000 people have been made sick and the epidemic was sourced to a river that runs next to the Nepalese camp in the central town of Mirebalais. The strain of cholera is the same as one endemic in Nepal.

The UN has had a huge mission in Haiti helping the impoverished country with its political strife and the impact of the January 2010 quake, which killed 250,000 people.

The United Nations has never acknowledged responsibility for the epidemic. It has insisted it was impossible to definitively pinpoint blame.

With a new surge in cholera deaths reported, the UN launched a $2.2 billion appeal in December however to raise money to provide clean water and health facilities in the Caribbean nation.

"The secretary general again expresses his profound sympathy for the terrible suffering caused by the cholera epidemic, and calls on all partners in Haiti and the international community to work together to ensure better health and a better future for the people of Haiti," Nesirky said.

Lawyers for the families of some of the dead and the sick made a compensation claim in November 2011.

The Institute for Justice and Democracy in Haiti, which is based in the US city of Boston, says it represents 5,000 victims and is demanding $100,000 for each death and $50,000 for people made sick.

Brian Concannon, a lawyer who heads the institute, told AFP "there is a long line of cases which says immunity cannot mean impunity," so the lawyers would pursue what is expected to become a protracted legal battle.

"This extreme interpretation of immunity is depriving our clients of any remedies for wrongs committed," Concannon added.

He said the institute would now file a case calling on a court to refuse to back the use of the 1946 convention on the UN's privileges and immunities as the global body had not provided an alternative path to seek compensation.

The action could be filed in Haiti, New York or a court in a European country such as Belgium or the Netherlands, he said.

Each one has advantages and disadvantages and we are not ready to make a decision yet," Concannon declared.

"Nine hundred people have died in the last year and the death rates for December and January were higher than for the previous December and January," the lawyer said.

"There is a sense of urgency and the legal liability of the UN is going to keep climbing because more people are getting sick, more are dying and they are refusing to respond. We are going to keep fighting as long as we have to," Concannon said.

Cholera, which causes potentially deadly diarrhea, is spread by ingesting food or water contaminated with a bacterium carried in human feces and spread through poor sanitation.