U.S. House Oversight and Reform Chairman Elijah Cummings, a key figure in the Democrats' impeachment inquiry and a fierce critic of President Donald Trump, has died, AP reported.

Cummings, 68, passed away Thursday at Johns Hopkins Hospital due to complications concerning long-standing health challenges, AP reported, citing a statement from his office.

The Maryland congressman's death comes as he was chairing one of the three panels that has been leading the House impeachment investigation focusing on Trump's Ukraine activities.