They have been described as explosive by the Labour leader
In one of the letters HSE boss Paul Reid expresses anger that NPHET announced an expansion of Coronavirus testing to 100,000 a week, without informing the HSE which carries out the tests.
Health Minister Simon Harris has played down any rift, saying a number of members of the HSE sit on NPHET which made the decision.
But Labour leader Alan Kelly says it shows a clear lack of communication at the top of medical decision making:
