Jailed Ukrainian opposition leader Yulia Tymoshenko says officials have confiscated two dosimeters, or radiation-measuring devices, from her hospital room during a search.
In a statement, Ms. Tymoshenko, a former prime minister, said Thursday that she had been using the devices to track her own radiation levels, saying she has recorded unusually high levels in the hospital ward where she is confined with back pain.
She said she had been planning to release the devices to her supporters so they could make her findings public. She blamed Ukrainian President Viktor Yanukovich for being behind the seizure of the dosimeters and any unusual radiation, saying he was the only one capable of taking such measures against her.
Ukraine's prison service confirmed the seizure of the devices from a hiding place in her room.
Last month Ukraine's high court rejected Ms. Tymoshenko's appeal against her conviction on charges of abuse of office. A judge said the court could not approve the appeal by Ms. Tymoshenko, who is serving a seven-year sentence.
The ruling came a day after her lawyers argued before the European Court for Human Rights that she was held before her trial illegally and under inhumane conditions.
The charges are linked to a natural gas deal she reached with Russia in 2009 while serving as prime minister. She faces separate charges of embezzlement and tax evasion.
Ms. Tymoshenko was a co-leader of the 2004 pro-democracy Orange Revolution. She says both cases are part of a political vendetta against her by President Yanukovych, who narrowly defeated her in a 2010 vote.