Deputy First Minister Michelle O’Neill is self-isolating after being in contact with a family member who tested positive for Covid-19.
Sinn Féin's leader in the north is to be tested for the virus and is expected to make a statement later today.
In a statement, Sinn Féin said: "Joint head of government Michelle O'Neill has confirmed that she is being tested for coronavirus and is self-isolating after contact with a family member who has tested positive for Covid-19.
"Michelle will continue to follow the public health advice and carry out her duties in government remotely."
Sinn Fein president Mary Lou McDonald said: "Michelle will be self-isolating and following all of the public health advice as she has been a close contact of somebody who has tested positive.
"We wish her well and her family well. May I say, as somebody who has contracted and was sick with this virus, it is not something I would wish on anybody. So I wish her well."
Ms O'Neill appeared with First Minister Arlene Foster at the Executive's daily Covid-19 briefing yesterday.
Last night Alliance Party leader Naomi Long said doctors told her she was probably infected with coronavirus earlier this year and suffered long Covid in the months that followed.
This morning new figures showed there have been 906 coronavirus-related deaths recorded in the north up to the end of last week.
