The United Nations expects the Guatemalan government will renew the Head of the International Commission Against Impunity, Cicig, Ivan Velasquez's visa.
"We understand that your visa has not been renewed and we truly hope the government renews it," said Stephane Dujarric, spokesman for the UN Secretary General, Antonio Guterres.
Dujarric said Guterres considers "the work of the Commission is extremely important".
In a letter sent to Cicig's administrative head German Suazo on Monday, Guatemala Foreign Ministry justified the decision saying that “the visa request was not filled by the relevant person.”
However, it did not say whether the state official was allowed to submit another visa request.
Migration authorities said Velasquez's documents expire next Wednesday, and he will only be able to stay if he can solve the situation before the deadline.
The UN-backed anti-graft body has been investigating alleged illicit campaign financing involving the Guatemalan President Jimmy Morales.
Morales attempted to expel Velasquez from the country in August claiming the Cicig was exceeding its mandate by opening the probe against him.
But the Constitutional Court eventually canceled the decision.
Morales has denied any wrongdoing.