Agriculture Minister Charlie Mc Conalogue has been confirmed to have Covid 19.
All cabinet ministers are now restricting their movements as a result.
A spokesperson says Minister Mc Conalogue has no symptoms and is self isolating.
It comes as the HSE warns the risk posed by the virus is at its highest point to date.
All ministers are restricting their movements following confirmation that a Cabinet colleague has tested positive.
They will do so until they have been tested and receive their results.
It comes as the Government urges people to reconsider their plans for Christmas.
Senior government official says Liz Canavan people planning to visit elderly relatives need to think twice.
HSE CEO Paul Reid says testing and tracing will continue throughout Christmas.
The Government says the decision to return to level 5 restrictions over Christmas was not taken lightly, but the increase in cases could not be ignored.
