diff --git a/CGAL_Core/include/CGAL/CORE/CoreAux.h b/CGAL_Core/include/CGAL/CORE/CoreAux.h
index 8577514dac0..b90d25656bf 100644
--- a/CGAL_Core/include/CGAL/CORE/CoreAux.h
+++ b/CGAL_Core/include/CGAL/CORE/CoreAux.h
@@ -156,12 +156,6 @@ CGAL_CORE_EXPORT double IntMantissa(double d);
 //      (See CORE_PATH/progs/ieee/frexp.cpp for details)
 CGAL_CORE_EXPORT int IntExponent(double d);
 
-/// Writes out an error or warning message in the local file CORE_DIAGFILE
-/** If last argument (err) is TRUE, then this is considered an error
- *  (not just warning).  In this case, the message is also printed in
- *  std::cerr, using std::perror().
- *  */
-CGAL_CORE_EXPORT void core_error(std::string msg, std::string file, int lineno, bool err);
 
 /// This is for debugging messages
 inline void core_debug(std::string msg){
diff --git a/CGAL_Core/include/CGAL/CORE/CoreAux_impl.h b/CGAL_Core/include/CGAL/CORE/CoreAux_impl.h
index b5bd45f13fe..e1fa64e5330 100644
--- a/CGAL_Core/include/CGAL/CORE/CoreAux_impl.h
+++ b/CGAL_Core/include/CGAL/CORE/CoreAux_impl.h
@@ -157,30 +157,5 @@ int IntExponent(double d) {
         return e-53;
 }
 
-/// core_error is the method to write Core Library warning or error messages
-/**         Both warnings and errors are written to a file called CORE_DIAGFILE.
- *        But errors are also written on std::cerr (similar to std::perror()).
- * */
-// Usage: core_error(message, file_with_error, line_number, err_type)
-//   where err_type=0 means WARNING, error_type=0 means ERROR
-CGAL_INLINE_FUNCTION
-void core_error(std::string msg, std::string file, int lineno, bool err) {
-  std::ofstream outFile(CORE_DIAGFILE, std::ios::app);  // open to append
-  if (!outFile) {
-     // perror("CORE ERROR: cannot open Core Diagnostics file");
-     std::cerr << "CORE ERROR: can't open Core Diagnostics file"<<std::endl;
-     std::exit(1); //Note: do not call abort()
-  }
-  outFile << "CORE " << (err? "ERROR" : "WARNING")
-     << " (at " << file << ": " << lineno << "): "
-     << msg << std::endl;
-  outFile.close();
-  if (err) {
-      (std::string("CORE ERROR") + " (file " + file + ", line "
-                   + std::to_string(lineno) +"):" + msg + "\n").c_str();
-     std::exit(1); //Note: do not call abort()
-  }
-}
-
 
 } //namespace CORE