The publisher, "Sergiy Vechirko," alleges the call took place on March 18 -- two days after Crimea's referendum calling for reunification with Russia. He also identifies the speakers as Tymoshenko and the former deputy secretary of Ukraine's National Security and Defense Council, Nestor Shufrych.
The conversation is mostly in Russian, with Shufrych bemoaning the state of affairs in Crimea before Tymoshenko brusquely cuts him off, saying, "Screw it, we should take up arms and kill the goddamned katsaps" -- derogatory Ukrainian slang for Russians -- "along with their leader."
She adds, "I'm sorry I'm not there right now -- there's no way they would have gotten Crimea away from me."
Shufrych goes on to say that a mutual acquaintance, "Viktor," asked what Kyiv should do about the 8 million Russians still living on Ukrainian territory.
"We should hit them with an atomic weapon," Tymoshenko answers back.
WATCH: A YouTube Posting Of Ukrainian Ex-Prime Minister Yulia Tymoshenko Speaking With Nestor Shufrych
Tymoshenko has acknowledged on Twitter that the phone call was real but said that the content was edited to appear virulently anti-Russian. Regarding the 8 million Russians, Tymoshenko claims her actual statement was "Russians in Ukraine are Ukrainians themselves." She added: "Hi FSB.: )"
Розмова була, але про 8 млн росіян в Україні - монтаж. Насправді сказала: росіяни в Україні - це українці.Привіт ФСБ:) Вибачте за нецензурне— Юлія Тимошенко (@YuliaTymoshenko) March 24, 2014
The sudden appearance of the recording on YouTube is reminiscent of last month's scandal in which two high-level diplomatic calls were recorded and leaked on social media, including one in which Assistant U.S. Secretary of State Victoria Nuland was caught saying, "F*** the EU."
Tymoshenko was freed from prison last month after her long-time rival, President Viktor Yanukovych, was ousted from power. She had spent nearly three years in jail on abuse of power charges her supporters said were politically motivated.
-- Daisy Sindelar