diff --git a/apps/openmw/mwbase/mechanicsmanager.hpp b/apps/openmw/mwbase/mechanicsmanager.hpp
index 84d43156e..d9068b285 100644
--- a/apps/openmw/mwbase/mechanicsmanager.hpp
+++ b/apps/openmw/mwbase/mechanicsmanager.hpp
@@ -225,6 +225,10 @@ namespace MWBase
             virtual bool isReadyToBlock (const MWWorld::Ptr& ptr) const = 0;
             virtual bool isAttackingOrSpell(const MWWorld::Ptr &ptr) const = 0;
 
+            /// Check if the target actor was detected by an observer
+            /// If the observer is a non-NPC, check all actors in AI processing distance as observers
+            virtual bool isActorDetected(const MWWorld::Ptr& actor, const MWWorld::Ptr& observer) = 0;
+
             virtual void confiscateStolenItems (const MWWorld::Ptr& player, const MWWorld::Ptr& targetContainer) = 0;
 
             /// List the owners that the player has stolen this item from (the owner can be an NPC or a faction).
diff --git a/apps/openmw/mwmechanics/actors.cpp b/apps/openmw/mwmechanics/actors.cpp
index 0cb7619db..1f9515417 100644
--- a/apps/openmw/mwmechanics/actors.cpp
+++ b/apps/openmw/mwmechanics/actors.cpp
@@ -1086,6 +1086,39 @@ namespace MWMechanics
         }
     }
 
+    bool Actors::isActorDetected(const MWWorld::Ptr& actor, const MWWorld::Ptr& observer)
+    {
+        if (!actor.getClass().isActor())
+            return false;
+
+        // If an observer is NPC, check if he detected an actor
+        if (!observer.isEmpty() && observer.getClass().isNpc())
+        {
+            return
+                MWBase::Environment::get().getWorld()->getLOS(observer, actor) &&
+                MWBase::Environment::get().getMechanicsManager()->awarenessCheck(actor, observer);
+        }
+
+        // Otherwise check if any actor in AI processing range sees the target actor
+        std::vector<MWWorld::Ptr> actors;
+        osg::Vec3f position (actor.getRefData().getPosition().asVec3());
+        getObjectsInRange(position, aiProcessingDistance, actors);
+        for(std::vector<MWWorld::Ptr>::iterator it = actors.begin(); it != actors.end(); ++it)
+        {
+            if (*it == actor)
+                continue;
+
+            bool result =
+                MWBase::Environment::get().getWorld()->getLOS(*it, actor) &&
+                MWBase::Environment::get().getMechanicsManager()->awarenessCheck(actor, *it);
+
+            if (result)
+                return true;
+        }
+
+        return false;
+    }
+
     void Actors::updateActor(const MWWorld::Ptr &old, const MWWorld::Ptr &ptr)
     {
         PtrActorMap::iterator iter = mActors.find(old);
diff --git a/apps/openmw/mwmechanics/actors.hpp b/apps/openmw/mwmechanics/actors.hpp
index 6eb3a2955..e433434a5 100644
--- a/apps/openmw/mwmechanics/actors.hpp
+++ b/apps/openmw/mwmechanics/actors.hpp
@@ -57,6 +57,10 @@ namespace MWMechanics
             PtrActorMap::const_iterator begin() { return mActors.begin(); }
             PtrActorMap::const_iterator end() { return mActors.end(); }
 
+            /// Check if the target actor was detected by an observer
+            /// If the observer is a non-NPC, check all actors in AI processing distance as observers
+            bool isActorDetected(const MWWorld::Ptr& actor, const MWWorld::Ptr& observer);
+
             /// Update magic effects for an actor. Usually done automatically once per frame, but if we're currently
             /// paused we may want to do it manually (after equipping permanent enchantment)
             void updateMagicEffects (const MWWorld::Ptr& ptr);
diff --git a/apps/openmw/mwmechanics/mechanicsmanagerimp.cpp b/apps/openmw/mwmechanics/mechanicsmanagerimp.cpp
index 5f3dd58af..5d9ef726a 100644
--- a/apps/openmw/mwmechanics/mechanicsmanagerimp.cpp
+++ b/apps/openmw/mwmechanics/mechanicsmanagerimp.cpp
@@ -423,6 +423,11 @@ namespace MWMechanics
         mObjects.update(duration, paused);
     }
 
+    bool MechanicsManager::isActorDetected(const MWWorld::Ptr& actor, const MWWorld::Ptr& observer)
+    {
+        return mActors.isActorDetected(actor, observer);
+    }
+
     bool MechanicsManager::isAttackPrepairing(const MWWorld::Ptr& ptr)
     {
         return mActors.isAttackPrepairing(ptr);
diff --git a/apps/openmw/mwmechanics/mechanicsmanagerimp.hpp b/apps/openmw/mwmechanics/mechanicsmanagerimp.hpp
index adad21916..1bf3a8d22 100644
--- a/apps/openmw/mwmechanics/mechanicsmanagerimp.hpp
+++ b/apps/openmw/mwmechanics/mechanicsmanagerimp.hpp
@@ -191,6 +191,10 @@ namespace MWMechanics
             /// Is \a ptr casting spell or using weapon now?
             virtual bool isAttackingOrSpell(const MWWorld::Ptr &ptr) const;
 
+            /// Check if the target actor was detected by an observer
+            /// If the observer is a non-NPC, check all actors in AI processing distance as observers
+            virtual bool isActorDetected(const MWWorld::Ptr& actor, const MWWorld::Ptr& observer);
+
             virtual void confiscateStolenItems (const MWWorld::Ptr& player, const MWWorld::Ptr& targetContainer);
 
             /// List the owners that the player has stolen this item from (the owner can be an NPC or a faction).
diff --git a/apps/openmw/mwscript/aiextensions.cpp b/apps/openmw/mwscript/aiextensions.cpp
index 76130be24..c98e0fc5a 100644
--- a/apps/openmw/mwscript/aiextensions.cpp
+++ b/apps/openmw/mwscript/aiextensions.cpp
@@ -372,21 +372,14 @@ namespace MWScript
 
                 virtual void execute (Interpreter::Runtime& runtime)
                 {
-                    MWWorld::Ptr observer = R()(runtime);
+                    MWWorld::Ptr observer = R()(runtime, false); // required=false
+
                     std::string actorID = runtime.getStringLiteral (runtime[0].mInteger);
                     runtime.pop();
 
                     MWWorld::Ptr actor = MWBase::Environment::get().getWorld()->getPtr(actorID, true);
 
-                    if(!actor.getClass().isActor() || !observer.getClass().isActor())
-                    {
-                        runtime.push(0);
-                        return;
-                    }
-
-                    Interpreter::Type_Integer value =
-                            MWBase::Environment::get().getWorld()->getLOS(observer, actor) &&
-                            MWBase::Environment::get().getMechanicsManager()->awarenessCheck(actor, observer);
+                    Interpreter::Type_Integer value = MWBase::Environment::get().getMechanicsManager()->isActorDetected(actor, observer);
 
                     runtime.push (value);
                 }