BOGOTA (Reuters) - Colombia has fired the head of a $500 million fund meant to finance post-conflict programs tied to the country’s peace deal with Marxist FARC rebels, after donor countries complained of irregularities and possible corruption.

The decision came after the ambassadors of Norway, Sweden and Switzerland wrote a letter to the government expressing concern over a lack of transparency and spending delays for the money, meant to fund reintegration of former Revolutionary Armed Forces of Colombia (FARC) fighters, crop substitution and other programs.

The FARC and the government signed a peace deal in late 2016 to end 50 years of fighting. More than 220,000 people were killed during the country’s civil war, in which the still-active rebel group the National Liberation Army and paramilitary gangs also fought.

“The government took the decision to remove Gloria Ospina from the executive direction of the Colombia in Peace Fund,” Colombian Vice President Oscar Naranjo told journalists on Monday.

Ospina was not reachable for comment late on Monday.

Colombia’s Finance Vice Minister Paula Acosta will join the fund’s committee and evaluate where it can improve, Naranjo said, in a bid to accelerate the distribution of resources and comply with transparency standards.

Doubts about the distribution of the funds could put future international donations in question at a time when Colombia is grappling with low economic growth.

Colombian Attorney General Nestor Humberto Martinez told journalists last week that there was a network of public servants benefiting personally from resources which should be destined for post-conflict programs.

The fund is financed from Colombia’s government budget, as well as donations from the United Nations, the European Union, the Inter-American Development Bank and the World Bank.

The Andean country has said it planned to invest more than $46 billion in post-conflict programs over the next 15 years, including the destruction of landmines, reintegration of more then 12,000 former FARC fighters and loyalists and rural development projects.