TEGUCIGALPA/GUATEMALA CITY (Reuters) - A Guatemalan presidential hopeful known for taking on high-profile corruption cases as attorney general said on Thursday she was detained at an airport in Honduras before abruptly leaving the country shortly afterward.

FILE PHOTO: Guatemalan Attorney General Thelma Aldana participates in a news conference in Guatemala City, Guatemala, August 28, 2017. REUTERS/Jose Cabezas/File Photo

Thelma Aldana, Guatemala’s former chief prosecutor, is among the front-runners in next month’s election but faces an arrest warrant back home that she dismisses as the work of her political opponents.

Aldana said in a post on her Twitter page she was “arbitrarily detained” in Honduras and lashed out at what she dubbed a “pact of the corrupt” in which she included Honduran President Juan Orlando Hernandez.

The Honduran migration institute confirmed in a statement that Aldana landed at the main airport in the capital on Thursday morning on a flight from neighboring El Salvador, was processed, and “voluntarily” left the country nearly three hours later and returned to El Salvador.

The statement noted twice that Aldana was traveling in a private plane.

The Honduran national police said in a separate statement Aldana was never detained and that there are no restrictions on her travel in the country.

A senior campaign aide said security officials questioned Aldana without identifying themselves.

“Thelma was taken to an office where she was interrogated several times and questioned about personal matters and security issues that put her at risk due to the information they were seeking,” campaign strategist Jose Carlos Marroquin told Reuters.

Aldana, 63, served as attorney general from 2014 to 2018 and helped topple a former president on corruption charges. She also investigated current President Jimmy Morales.

A Guatemalan judge issued a warrant for Aldana’s arrest last month on charges including embezzlement and tax fraud.

She has dismissed the order as politically motivated, along with a separate ruling last week by Guatemala’s electoral tribunal that revoked her candidacy citing irregularities during her tenure as attorney general.

She has appealed against the electoral tribunal’s ruling to the constitutional court, Guatemala’s top court.

Aldana led the field of presidential candidates with 28 percent in a recent poll before the June 16 election, ahead of Zury Rios, the daughter of former dictator Efrain Rios Montt, and former First Lady Sandra Torres.

Running on a platform of efficient and transparent government, Aldana has pledged to expand the U.N.-backed International Commission Against Impunity in Guatemala, or CICIG.

Morales’ government announced in January it would not renew the CICIG’s mandate and expelled the anti-corruption body’s leader.