"Michael Lipman, Alex Crockett and Andrew Higgins had been required to appear at an internal disciplinary hearing today to address the failure on three occasions to take a drugs test following allegations surrounding player conduct on Sunday, May 10," said Calleja.
"Immediately before the hearings were due to take place the players resigned from the Club with immediate effect. The Club regards this as an internal matter and intends to make no further comment"
Lipman becomes the second England international to be lost in controversial circumstances by Bath this year.
Earlier in the season their England and Lions prop Matt Stevens was handed a two year ban when a sample he provided at a Heineken Cup game in Glasgow before Christmas tested positive for cocaine.