Colombia offered asylum Monday to Venezuela's sacked chief prosecutor Luisa Ortega, who fled her country after defying President Maduro.
"Luisa Ortega is under the protection of the Colombian government. If she asks for asylum, we will grant it to her," Colombia's President Juan Manuel Santos said on Twitter.
A former loyalist of the socialist leadership, the 59-year-old Ortega had become Maduro's most high-ranking critic in Venezuela.
Immigration officials in Colombia said she arrived in the country on Friday with her husband, lawmaker German Ferrer, on a private flight from the Dutch Caribbean island of Aruba.
Ferrer himself faces an arrest warrant issued by the pro-Maduro Supreme Court.
Venezuelan authorities had banned Ortega from traveling abroad, prompting her to allege "political persecution."
Maduro has faced months of deadly mass protests by opponents who blame him for an economic crisis and are demanding elections to replace him.
Last month, he set up a new constitutional authority packed with his allies, which a few days later removed Ortega from her post.
Ortega hit back on Friday by claiming she had evidence implicating Maduro and his inner circle in an international bribery scandal involving Brazilian construction firm Odebrecht.
Colombia's Santos has joined other regional and world powers in criticizing Maduro.
Maduro's critics accuse him of clinging to power through undemocratic means in a country stricken by shortages of food and medicine.
Venezuela's center-right-led MUD opposition coalition accuses security forces of beating and killing protesters.
Clashes between protesters and police this year have left nearly 130 people dead, according to prosecutors.