Samsung Group on Thursday formally denied rumors that Samsung Electronics Chairman Lee Kun-hee has died.

A senior official of the corporate group said the rumor circulating in the stock bourses is completely untrue.

Earlier Thursday, rumors that Lee's death will be announced at 3 p.m. quickly spread on social media and affected share prices of Samsung Group's affiliates.

The Samsung chief collapsed in May 2014 due to acute myocardial infarction. He has yet to regain consciousness as he continues to receive rehabilitation treatment at the Samsung Medical Center.

Since the rumor of his death emerged around noon, Samsung C&T Corporation's stock price surged to the eight percent range by 1 p.m. The share prices of Samsung SDS also jumped to the seven percent range during Thursday trading.