Ukraine police investigating possible surveillance of Yovanovitch, Russian hacking The investigation comes after the release of text messages from Lev Parnas.

Ukrainian police are now investigating two major cases related to the impeachment trial of President Donald Trump, one around possible illegal surveillance of former U.S. Ambassador to Ukraine Marie Yovanovitch and the other around a suspected attack by Russian military hackers targeting a company where the son of former Vice President Joe Biden sat on the board.

On the Yovanovitch case, the interior ministry said in a statement Thursday that police had opened a criminal investigation in light of text messages released by Democrats on the House Intelligence Committee this week between two associates of President Donald Trump's personal lawyer Rudy Giuliani.

On the alleged hacking case, Ukrainian police said Thursday they were now investigating a suspected attack by Russian military hackers that targeted Burisma, the Ukraine-based energy company that employed Hunter Biden.

Earlier this week, cyber-security firm Area 1 said it had discovered that hackers who appeared to be from Russia's military agency, the GRU, had mounted a concerted phishing campaign against Burisma employees, trying to break into their emails and collect data.

The attacks occurred at the height of the impeachment hearings in November, and Area 1 speculated that the Russian hackers were searching for material that could be damaging to the Bidens that could then be leaked, following a model they had used in the 2016 election against the Democrat candidate Hillary Clinton.

Ukraine's cyber police said it believed the attack -- which also targeted Kvartal 95, the production company that produced President Volodymyr Zelenskiy's TV show before the former actor was elected -- was "probably committed by the Russian special services" and they were in the process of identifying the people involved. It said Ukraine had also asked the FBI to join the investigation.

Meanwhile, in the text messages released by the House committee this week, Republican congressional candidate Robert Hyde appeared to suggest to Lev Parnas, a Florida businessman now at the center of the impeachment controversy, that he had people following Ambassador Yovanovitch's movements in Ukraine.

Ukrainian police are now looking to see if there was surveillance and, if so, whether it had violated Ukrainian law or international conventions obliging host countries to protect foreign diplomats there, the ministry said.

"Ukraine's position is not to interfere in the domestic affairs of the United States of America. However, the published records contain the fact of possible violation of the legislation of Ukraine and the Vienna Convention on Diplomatic Relations, which protects the rights of a diplomat in the territory of another country," the ministry's statement said.

"After analyzing these materials, the National Police of Ukraine upon their publication started criminal proceedings under part 2 of Art. 163 (Violation of the secrecy of correspondence, telephone conversations, telegraph or other correspondence) and part 1 of Art. 182 (Unlawful collection, storage, use of confidential information about a person, violation of privacy) of the Criminal Code of Ukraine," the statement continues.

The ministry said investigators were examining whether any laws had been broken or if the messages had simply been "bravado and fake in an informal conversation between two US citizens." Ukraine's Interior Minister Arsen Avakov has requested the U.S.' assistance in the investigation, it said.

The allegations that the Giuliani associates may have been spying on a U.S. diplomat are potentially explosive for Trump, coming as the trial for his impeachment begins in the Senate.

Parnas, a Soviet-born businessperson based in Florida, took part in Giuliani's campaign to press the Ukrainian government to open investigations into Biden.

Parnas has said he and Giuliani were seeking to have Yovanovitch removed as ambassador at the same time, having deemed her an obstacle to their effort. Yovanovitch was recalled abruptly by Trump before the end of her term last year and has testified in the impeachment inquiry that she believed she was the victim of a deliberate smear campaign.

In the messages from March and April released by the House Committee, Hyde, a supporter of Trump, and Parnas also discuss their desire to have Trump fire Yovanovitch, lamenting that she had not yet been removed. In the course of those messages, Hyde then gave a series of updates on Yovanovitch that suggested he or others were watching her in Kyiv and perhaps monitoring her communications.

"She's talked to three people. Her phone is off. Her computer is off," Hyde wrote in one message.

In others, Hyde, who referred to Yovanovitch as a "b----," noted Yovanovitch's heavy security, and in another said, "We have a person inside."

Several of Hyde's messages suggested had other people in Kyiv tracking the ambassador.

"My contacts are asking what are the next steps because they cannot keep going to check people will start to ask questions," he wrote.

Hyde repeatedly asked Parnas what "next steps" were, saying that the unidentified people were "willing to help if we/you would like a price," and "guess you can do anything in Ukraine with money ... is what I was told."

Parnas texted back: "lol."

Since the messages' release, Hyde has dismissed them as joking around with Parnas.

"I was never in Kiev," he wrote on Twitter Wednesday. "For them to take some texts my buddy's [sic] and I wrote back to some dweeb we were playing with that we met a few times while we had a few drinks is definitely laughable."

Yovanovitch through her lawyer has called the text messages between Parnas and Hyde "disturbing" and called for them to be investigated.

"We trust that the appropriate authorities will conduct an investigation to determine what happened," Lawrence S. Robbins, Yovanovitch's attorney, said in a statement.

In an interview with MSNBC's Rachel Maddow on Wednesday, Parnas apologized to Yovanovitch for the smear and disinformation campaign against her. In the explosive interview, he also claimed that Trump had been aware of all he and Giuliani's efforts.

"He was aware of all of my movements," Parnas said. "I wouldn't do anything without the help of Rudy Giuliani or the president."

Parnas has suggested he would be willing to be called as a witness in the Senate impeachment trial. He and his fellow Soviet-born business partner, Igor Fruman, last year were indicted on charges of conspiracy, making false statements and falsification of records, in a case where prosecutors allege the made large campaign donations to Republican candidates after receiving millions of dollars originating from Russia. Both men have denied the charges.

Democrats have condemned the possibility that Yovanovitch was being spied on and promised to investigate.

Sen. Bernie Sanders on Wednesday called the situation "outrageous."

"This must be fully investigated as the Senate conducts the impeachment trial," he tweeted. "We have a responsibility to hold this lawless administration to account."

The developments once again thrust Ukraine into U.S. politics, a place its leadership under President Zelenskiy, has been at pains to try to avoid.