Ukrainian law enforcers have shut down a criminal investigation into Joe Biden, who was accused of improperly forcing the dismissal of prosecutor general Vitkor Shokin in 2016, a spokesperson for the national police has said.

The investigation was launched in February after the ousted prosecutor, Viktor Shokin, appealed to a court, NBC News reports.

Under Ukrainian law, anyone can go to court to request an investigation if the State Investigative Bureau declines to open one on its own.

The courts overwhelmingly order law enforcement to launch criminal cases even in the absence of evidence, according to Vitaly Shabunin, the co-founder of the Anti-Corruption Action Center, a Kyiv-based rights watchdog.

Read alsoU.S. slaps sanctions on MP Andriy DerkachU.S. President Trump earlier pressured his Ukrainian counterpart Volodymyr Zelensky to announce a probe of this kind last year, a move that led to Trump's impeachment by the House of Representatives.

Shokin was a central figure in Rudy Giuliani’s campaign to sully Biden, one of the main threads of the impeachment proceedings. The ex-top prosecutor claimed the former vice president pressured Ukraine's now ex-president Petro Poroshenko to fire him for investigating a gas company Burisma where Biden's son Hunter was on the board of directors until 2019.

Shokin has claimed he was forced to step down after he started looking into Hunter Biden's role at Burisma, while a deputy prosecutor working under Shokin has said the case had been dormant at the time the U.S. was pushing for Shokin's removal.

Multiple western governments, including the Obama administration, had at the time demanded Shokin be replaced for failing to prosecute corruption cases, and Ukrainian investigators and anti-corruption watchdogs have said that Shokin was fired because he had made no progress in the fight against corruption.