diff --git a/libraries/AP_NavEKF2/AP_NavEKF2.cpp b/libraries/AP_NavEKF2/AP_NavEKF2.cpp
index f9709a1728..e4838b9a44 100644
--- a/libraries/AP_NavEKF2/AP_NavEKF2.cpp
+++ b/libraries/AP_NavEKF2/AP_NavEKF2.cpp
@@ -768,19 +768,6 @@ bool NavEKF2::getHeightControlLimit(float &height) const
     return core->getHeightControlLimit(height);
 }
 
-// provides the quaternion that was used by the INS calculation to
-// rotate from the previous orientation to the orientaion at the
-// current time step
-// returns a zero rotation quaternion if the INS
-// calculation was not performed on that time step.
-Quaternion NavEKF2::getDeltaQuaternion(void) const
-{
-    if (!core) {
-        return Quaternion();
-    }
-    return core->getDeltaQuaternion();
-}
-
 // return the amount of yaw angle change due to the last yaw angle reset in radians
 // returns true if a reset yaw angle has been updated and not queried
 // this function should not have more than one client
diff --git a/libraries/AP_NavEKF2/AP_NavEKF2.h b/libraries/AP_NavEKF2/AP_NavEKF2.h
index ac88420518..6e26869aa5 100644
--- a/libraries/AP_NavEKF2/AP_NavEKF2.h
+++ b/libraries/AP_NavEKF2/AP_NavEKF2.h
@@ -216,10 +216,6 @@ public:
     // this is needed to ensure the vehicle does not fly too high when using optical flow navigation
     bool getHeightControlLimit(float &height) const;
 
-    // provides the quaternion that was used by the INS calculation to rotate from the previous orientation to the orientaion at the current time step
-    // returns a zero rotation quaternion if the INS calculation was not performed on that time step.
-    Quaternion getDeltaQuaternion(void) const;
-
     // return the amount of yaw angle change due to the last yaw angle reset in radians
     // returns true if a reset yaw angle has been updated and not queried
     // this function should not have more than one client
diff --git a/libraries/AP_NavEKF2/AP_NavEKF2_core.cpp b/libraries/AP_NavEKF2/AP_NavEKF2_core.cpp
index 55bf754087..723718e96c 100644
--- a/libraries/AP_NavEKF2/AP_NavEKF2_core.cpp
+++ b/libraries/AP_NavEKF2/AP_NavEKF2_core.cpp
@@ -4807,14 +4807,6 @@ bool NavEKF2_core::getHeightControlLimit(float &height) const
     }
 }
 
-// provides the delta quaternion that was used by the INS calculation to rotate from the previous orientation to the orientation at the current time
-// the delta quaternion returned will be a zero rotation if the INS calculation was not performed on that time step
-Quaternion NavEKF2_core::getDeltaQuaternion(void) const
-{
-    // Note: correctedDelAngQuat is reset to a zero rotation at the start of every update cycle in UpdateFilter()
-    return correctedDelAngQuat;
-}
-
 // return the quaternions defining the rotation from NED to XYZ (body) axes
 void NavEKF2_core::getQuaternion(Quaternion& ret) const
 {
diff --git a/libraries/AP_NavEKF2/AP_NavEKF2_core.h b/libraries/AP_NavEKF2/AP_NavEKF2_core.h
index 66a32f8567..63ad5c9f0b 100644
--- a/libraries/AP_NavEKF2/AP_NavEKF2_core.h
+++ b/libraries/AP_NavEKF2/AP_NavEKF2_core.h
@@ -209,10 +209,6 @@ public:
     // this is needed to ensure the vehicle does not fly too high when using optical flow navigation
     bool getHeightControlLimit(float &height) const;
 
-    // provides the quaternion that was used by the INS calculation to rotate from the previous orientation to the orientaion at the current time step
-    // returns a zero rotation quaternion if the INS calculation was not performed on that time step.
-    Quaternion getDeltaQuaternion(void) const;
-
     // return the amount of yaw angle change due to the last yaw angle reset in radians
     // returns true if a reset yaw angle has been updated and not queried
     // this function should not have more than one client