The Mines Awareness Trust (MAT) charity, based in Guernsey, is due to close at the end of 2010.
MAT has been globally recognised for its lifesaving work with landmines and unexploded ordnance since it was launched in 1999.
Its work included a pivotal role in helping Rwanda being declared the world's 'first mine-free country'.
Founder Ben Remfrey MBE said the closure was due to a lack of funding and was "a sign of the times".
Mr Remfrey ranked Rwanda top of all the charities work: "To come into a country where all others had previously failed.
"Revitalise a project and be the sole advisors and implementers with the National Government and its military and to achieve our objective, the final clearance of the country, was remarkable."
MAT has also worked in Afghanistan, Angola, Eritrea, Kenya, Kosovo, Sri Lanka, The Democratic Republic of Congo, the Sudan and Zimbabwe.
In the last three years £250,000 had been raised for the charity by volunteers, but Mr Remfrey said increasing costs and its lack of governmental support were major factors in the decision.
He said: "The level of funding required to run operations, mostly in challenging environments, is much higher than it was in 1999.
"The Trust has become a victim of its own success to a degree, whilst all other mine action agencies get government support, this was not the case with MAT."
Mr Remfrey said the Guernsey Overseas Aid Commission had provided grant funding but only for specific projects.
Maj Gen Griff Caldwell, MAT chairman, said: "Guernsey can be proud of the Mines Awareness Trust, which has achieved so much in many dangerous parts of the world in the past 11 years.
"Operating in global mine action is not a simple matter, it requires strict adherence to many drills, standards and procedures.
"It is much to MAT's credit that up until now it has not suffered any casualties and maintains a 100% safety record, which is unique in its field.
"Without the support of a large number of people in Guernsey and also in the UK the success of MAT would not have been achieved."
Mr Remfrey and his team will continue their work in a commercial capacity under the name MAT Mondial.