SEOUL -- South Korea's highest court on Thursday upheld the acquittal of Samsung Electronics chief Lee Jae-yong after he was cleared of a slew of charges linked to a controversial merger, ending a years-long legal drama at the tech titan.

Prosecutors claimed the deal was designed to seal control of the company for Lee, at a cost to shareholders, accusing the 57-year-old of stock price rigging, breach of trust, and accounting fraud.

He was originally cleared of the charges at a trial late last year and that was upheld by an appeal court in February, a decision that was challenged by prosecutors.

However, the Supreme Court upheld the original decision on Thursday, bringing an end to the saga.

"All appeals were dismissed and the lower court's rulings were upheld," court documents said.

The charges related to the 2015 merger between Samsung C&T -- a construction and engineering firm -- and Cheil Industries.

Lee did not appear at the court, but Samsung's legal team welcomed the ruling, saying it "clearly affirms the legality of the merger between Samsung C&T and the accounting practices of Samsung Biologics".

"We express our sincere gratitude to the court for its wise and thorough judgement after five years of careful deliberation," they added.

Agencies