Police detained former Vice President Roxana Baldetti on Friday in connection with a customs corruption scandal that led to her resignation after her private secretary was implicated.
Prosecutor's office spokeswoman Julia Barrera confirmed the arrest and said more details would be released later. Baldetti is suspected of illicit association, customs fraud and graft.
The office said prosecutor Francisco Sandoval informed Baldetti of her detention at a hospital where she was seeking treatment for health problems.
Baldetti has denied involvement in the scandal at the customs agency, which involved kickbacks paid by businesspeople in return for lower import duties.
Prosecutors also said they have asked for President Otto Perez Molina's immunity of office to be withdrawn to allow for him to be investigated in the same case.
Perez Molina, too, has denied involvement, and a recent, separate bid to lift his immunity died in Congress last week.
The ring known as "La Linea," or "The Line," was allegedly masterminded by Baldetti's aide, Juan Carlos Monzon Rojas, who is currently a fugitive.
Baldetti resigned May 8 after an investigation spearheaded by prosecutors and a U.N. commission probing criminal networks in Guatemala led to arrests of government officials and private citizens.
The U.N. commission has presented wiretap conversations related to the investigation in which participants mention "the R," ''the No. 2" and "the lady," suspected references to the vice president.
Guatemala has seen large protests over the scandal and another corruption investigation that rocked the nation's social security institute.