The European Union's enlargment commissioner, Stefan Fuele, has expressed concern about the discharge of Ukraine's jailed former Interior Minister Yuriy Lutsenko from the hospital.
Fuele sent a tweet on January 30, noting the discharge came "so soon after serious surgery."
Doctors removed a growth from Lutsenko's intestines at a Kyiv clinic on January 23.
Lutsenko's wife, Iryna Lutsenko, says doctors found three ulcers in her husband's stomach and planned to perform a second surgery but that Lutsenko was unexpectedly transferred back to prison.
Officials from Ukraine's Penitentiary Service say Lutsenko can receive further medical treatment in prison.
Lutsenko is serving a four-year prison term for embezzlement, abuse of office, and ordering illegal surveillance of suspects while investigating the poisoning of Viktor Yushchenko before his victory in the 2004 presidential campaign.
Lutsenko denies any wrongdoing, calling his imprisonment politically motivated.
Based on reporting by UNIAN and Interfax