Tymoshenko is serving a seven-year prison sentence at a penal colony in Ukraine. She was found guilty of abusing her authority when she helped broker a natural gas deal with Russian energy company Gazprom in 2009.
The U.S. government called on Kiev to let U.S. representatives meet Tymoshenko in prison. Yevgenia Tymoshenko, daughter of the jailed leader, told Radio Free Europe/Radio Liberty last week that Yulia Tymoshenko has several large bruises on her body, including fingerprint bruises on her arm and a 4-inch bruise on her abdomen. She was allegedly roughed up by prison authorities.
"The United States is deeply concerned by the treatment of former Prime Minister Yulia Tymoshenko and other imprisoned members of her former government," a statement attributed to U.S. Secretary of State Hillary Clinton read.
European and Russian leaders have expressed similar concerns. Tymoshenko is said to be on a hunger strike protesting her situation. She denies the charges and her Western supporters believe they're politically motivated.
Tymoshenko lead the Orange Revolution in 2005. She later lost a tense campaign for president to Viktor Yanukovych, her former revolutionary ally, in 2010.