Conor Murphy is to stand down as Economy Minister, First Minister Michelle O'Neill has said.
He is stepping down immediately on "medical grounds," the Sinn Féin deputy leader added.
HIs party colleague Deirdre Hargey will take on the role on an interim basis.
On Tuesday, Mr Murphy told the UK Covid Inquiry he would not be appearing before it "on medical advice". He also had to miss a scheduled appearance in the Northern Ireland Assembly.
"Conor has been advised by his doctor to rest and will undergo further medical tests," Ms O'Neill said.
"My colleagues and I all wish Conor a full and speedy recovery."