WASHINGTON - Ukrainian legal experts say they are bemused by reports of American back-channel pressure to pursue an investigation of an energy company linked to the son of U.S. presidential candidate Joe Biden, pointing out the Trump administration could have easily achieved its goal through established legal channels.

The lawyers say there is a well-established tradition of cooperation between the two countries in criminal investigations, based on the provisions of a Mutual Legal Assistance Treaty (MLAT) signed by the two countries in 1998.

"This treaty extensively regulates all issues related to cooperation and communication between [signatory nations] on criminal investigations," said Ukrainian defense attorney Denys Bugay, a specialist in multijurisdictional proceedings.

"The treaty authorizes the U.S. Department of Justice and Ukraine's General Prosecutor Office ... or the agencies they delegate this responsibility to communicate. If one country thinks that it has or needs information important to criminal investigation, the communication should take place within the framework of this treaty and according to the instruments it provides."

Normal procedure

In a normal case where the United States seeks assistance in investigating an American citizen, he and other lawyers said, the U.S. Justice Department would open a case within its own jurisdiction and then ask Ukraine for help under the MLAT.

If the United States had followed these procedures in the case of the energy company Burisma and Biden's son, Hunter, there is little doubt that Ukrainian law enforcement authorities would have fully cooperated, the lawyers said.

That was the experience of American lawyers when they sought Ukrainian help in the successful money-laundering prosecution of Ukraine's former prime minister, Pavlo Lazarenko, according to Martha Boersch, a lead prosecutor on the case and currently an attorney with the California-based Boersch and Illovsky LLP law firm.

She described MLAT requests as a routine matter in which U.S. attorneys draft a request for mutual legal assistance and send it to the Office of International Affairs at the U.S. Department of Justice.

"They review it, they then forward that request to the central authority in Ukraine, which would be the General Prosecutor Office," she told VOA. "They would review it and decide if they can execute it themselves or send it to a local prosecutor. And that might mean getting documents sent or witnesses interviewed."

While localized legal or political considerations can affect the execution of MLAT requests, Boersch says she found that Ukrainian law enforcement agencies were typically transparent and responsive.

"The process was not difficult; they were forthcoming," she said. "We did not have any serious problems getting information from Ukraine."

Why go outside?

This has left the Ukrainian lawyers to puzzle over why Rudy Giuliani, President Donald Trump's personal lawyer, would have gone outside the normal channels to press Ukrainian authorities to open an investigation into Burisma and Hunter Biden, who served on the company's board.

Oleksiy Shevchuk, a managing partner with Kyiv-based Barrister LLC, believes Giuliani may have chosen the indirect route because the evidentiary threshold for justifying a probe in Ukraine is lower than it is in the United States.

Since the Soviet era, Shevchuk told VOA, even the loosest of pretexts could justify an investigation by Ukrainian prosecutors. But even then, he said, "it's hard to investigate something that has such little relation to Ukraine."

Kostiantyn Likarchuk, an experienced international litigator in the Kyiv office of the Kinstellar law firm, also pointed out that Burisma is an offshore-registered holding company and that there is no evidence of a crime committed in Ukraine by Hunter Biden.

"What could be the subject of the Ukrainian investigation? I don't think anybody understands it," he said.

However, Bugay, a specialist in multijurisdictional proceedings, said if the Ukraine prosecutor's office decides a crime took place within the country, it can indict anyone involved, regardless of the person's citizenship. "I have Ukrainian clients who were indicted in Belarus and Russia, and Russian citizens indicted in Ukraine," he said.

Original probe

Likarchuk said the original investigation of Burisma in 2012 - before Biden joined the board - concerned the suspected abuse of special subsoil land-use permits by the company's owner, who at the time was Ukraine's ecology minister. Therefore, the case and some others related to Burisma fell within Ukraine's legal jurisdiction, he said.

The U.S. has provided support for the structural reform of Ukraine's legal and law enforcement systems.

American officials were directly involved in the 2014 creation of the National Anti-Corruption Bureau of Ukraine (NABU), whose detectives underwent training sponsored by the U.S. Federal Bureau of Investigation.

The U.S. departments of State, Justice, Treasury and others all have representatives stationed in Ukraine.