Veteran US Democratic congressman Elijah Cummings, who was heavily involved with the Trump impeachment inquiry, has died at the age of 68.
His office said he had died as a result of “longstanding health challenges”.
As chairman of the House of Representatives Oversight Committee, he had instigated several investigations into the Trump administration.
He also clashed with administration officials over healthcare and immigration.
Earlier this year, during a hearing about migrant detention, Mr Cummings blasted acting Homeland Security Secretary Kevin McAleenan, asking him if the department had an “empathy deficit”.
President Donald Trump responded with a week-long series of tweets and comments attacking the congressman and labelling his majority-black Baltimore district a “disgusting, rat and rodent-infested mess”. Several Democratic lawmakers labelled the comment as racist.
The congressman had experienced several health problems in recent years, and received treatment for a heart condition.
Prominent Democratic lawmakers have paid tribute to Mr Cummings following the news of his death.
“He worked until his last breath because he believed our democracy was the highest and best expression of our collective humanity,” Maryland’s Democratic Party chairwoman, Maya Cummings, said in a statement.
Mr Cummings worked as a Maryland state delegate and lawyer before his election to the House of Representatives in 1996.
A Baltimore native, he was one of seven children born to parents who were farm workers on the same land where their ancestors were enslaved.
He had served as chairman of the Oversight Committee since January after Democrats took control of the House.
During his tenure, he engaged in a lengthy court battle with the Trump administration over subpoenas of the president’s personal and financial records