diff --git a/src/core/border_router/routing_manager.cpp b/src/core/border_router/routing_manager.cpp
index c0750c774..7e96f85d4 100644
--- a/src/core/border_router/routing_manager.cpp
+++ b/src/core/border_router/routing_manager.cpp
@@ -825,7 +825,7 @@ bool RoutingManager::ShouldProcessRouteInfoOption(const RouteInfoOption &aRio, c
     // both checks are necessary.
 
     VerifyOrExit(!mRioAdvertiser.HasAdvertised(aPrefix));
-    VerifyOrExit(!Get<RoutingManager>().NetworkDataContainsOmrPrefix(aPrefix));
+    VerifyOrExit(!Get<NetworkData::Leader>().ContainsOmrPrefix(aPrefix));
 
     shouldProcess = true;
 
@@ -848,24 +848,6 @@ exit:
     return;
 }
 
-bool RoutingManager::NetworkDataContainsOmrPrefix(const Ip6::Prefix &aPrefix) const
-{
-    NetworkData::Iterator           iterator = NetworkData::kIteratorInit;
-    NetworkData::OnMeshPrefixConfig onMeshPrefixConfig;
-    bool                            contains = false;
-
-    while (Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, onMeshPrefixConfig) == kErrorNone)
-    {
-        if (IsValidOmrPrefix(onMeshPrefixConfig) && onMeshPrefixConfig.GetPrefix() == aPrefix)
-        {
-            contains = true;
-            break;
-        }
-    }
-
-    return contains;
-}
-
 bool RoutingManager::NetworkDataContainsUlaRoute(void) const
 {
     // Determine whether leader Network Data contains a route
@@ -2127,28 +2109,7 @@ bool RoutingManager::OmrPrefixManager::ShouldAdvertiseLocalAsRio(void) const
     // may still be present in Network Data for a short interval due
     // to delays in registering changes with the leader.
 
-    bool                            shouldAdvertise = false;
-    NetworkData::Iterator           iterator        = NetworkData::kIteratorInit;
-    NetworkData::OnMeshPrefixConfig prefixConfig;
-
-    VerifyOrExit(mIsLocalAddedInNetData);
-
-    while (Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, prefixConfig) == kErrorNone)
-    {
-        if (!IsValidOmrPrefix(prefixConfig))
-        {
-            continue;
-        }
-
-        if (prefixConfig.GetPrefix() == mLocalPrefix.GetPrefix())
-        {
-            shouldAdvertise = true;
-            break;
-        }
-    }
-
-exit:
-    return shouldAdvertise;
+    return mIsLocalAddedInNetData && Get<NetworkData::Leader>().ContainsOmrPrefix(mLocalPrefix.GetPrefix());
 }
 
 Error RoutingManager::OmrPrefixManager::AddLocalToNetData(void)
diff --git a/src/core/border_router/routing_manager.hpp b/src/core/border_router/routing_manager.hpp
index a814b5452..3c7d2f3ca 100644
--- a/src/core/border_router/routing_manager.hpp
+++ b/src/core/border_router/routing_manager.hpp
@@ -1399,7 +1399,6 @@ private:
     bool ShouldProcessPrefixInfoOption(const PrefixInfoOption &aPio, const Ip6::Prefix &aPrefix);
     bool ShouldProcessRouteInfoOption(const RouteInfoOption &aRio, const Ip6::Prefix &aPrefix);
     void UpdateDiscoveredPrefixTableOnNetDataChange(void);
-    bool NetworkDataContainsOmrPrefix(const Ip6::Prefix &aPrefix) const;
     bool NetworkDataContainsUlaRoute(void) const;
     void UpdateRouterAdvertHeader(const RouterAdvert::RxMessage *aRaMsg, RouterAdvOrigin aRaOrigin);
     void ResetDiscoveredPrefixStaleTimer(void);
diff --git a/src/core/thread/network_data_leader.cpp b/src/core/thread/network_data_leader.cpp
index 0c08a6175..187e431c2 100644
--- a/src/core/thread/network_data_leader.cpp
+++ b/src/core/thread/network_data_leader.cpp
@@ -607,5 +607,40 @@ void Leader::SignalNetDataChanged(void)
     Get<ot::Notifier>().Signal(kEventThreadNetdataChanged);
 }
 
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
+
+bool Leader::ContainsOmrPrefix(const Ip6::Prefix &aPrefix) const
+{
+    bool                   contains = false;
+    const PrefixTlv       *prefixTlv;
+    const BorderRouterTlv *brSubTlv;
+
+    VerifyOrExit(BorderRouter::RoutingManager::IsValidOmrPrefix(aPrefix));
+
+    prefixTlv = FindPrefix(aPrefix);
+    VerifyOrExit(prefixTlv != nullptr);
+
+    brSubTlv = prefixTlv->FindSubTlv<BorderRouterTlv>(/* aStable */ true);
+
+    VerifyOrExit(brSubTlv != nullptr);
+
+    for (const BorderRouterEntry *entry = brSubTlv->GetFirstEntry(); entry <= brSubTlv->GetLastEntry(); entry++)
+    {
+        OnMeshPrefixConfig config;
+
+        config.SetFrom(*prefixTlv, *brSubTlv, *entry);
+
+        if (BorderRouter::RoutingManager::IsValidOmrPrefix(config))
+        {
+            ExitNow(contains = true);
+        }
+    }
+
+exit:
+    return contains;
+}
+
+#endif // OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
+
 } // namespace NetworkData
 } // namespace ot
diff --git a/src/core/thread/network_data_leader.hpp b/src/core/thread/network_data_leader.hpp
index 597689199..72610fc62 100644
--- a/src/core/thread/network_data_leader.hpp
+++ b/src/core/thread/network_data_leader.hpp
@@ -421,21 +421,24 @@ public:
      */
     const ServiceTlv *FindServiceById(uint8_t aServiceId) const;
 
-#if OPENTHREAD_FTD && OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
+#endif // OPENTHREAD_FTD
+
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     /**
-     * Indicates whether a given Prefix can act as a valid OMR prefix and exists in the network data.
+     * Indicates whether Network Data contains a valid OMR prefix.
+     *
+     * If the given @p aPrefix is itself not a valid OMR prefix, this method will return `false`, regardless of
+     * whether the prefix is present in the Network Data.
      *
      * @param[in]  aPrefix   The OMR prefix to check.
      *
-     * @retval TRUE  If @p aPrefix is a valid OMR prefix and Network Data contains @p aPrefix.
-     * @retval FALSE Otherwise.
+     * @retval TRUE   Network Data contains a valid OMR prefix entry matching @p aPrefix.
+     * @retval FALSE  Network Data does not contain a valid OMR prefix entry matching @p aPrefix.
      *
      */
     bool ContainsOmrPrefix(const Ip6::Prefix &aPrefix) const;
 #endif
 
-#endif // OPENTHREAD_FTD
-
 private:
     using FilterIndexes = MeshCoP::SteeringData::HashBitIndexes;
 
diff --git a/src/core/thread/network_data_leader_ftd.cpp b/src/core/thread/network_data_leader_ftd.cpp
index 5905ced3d..11803c693 100644
--- a/src/core/thread/network_data_leader_ftd.cpp
+++ b/src/core/thread/network_data_leader_ftd.cpp
@@ -1358,41 +1358,6 @@ void Leader::HandleTimer(void)
     }
 }
 
-#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
-
-bool Leader::ContainsOmrPrefix(const Ip6::Prefix &aPrefix) const
-{
-    bool                   contains = false;
-    const PrefixTlv       *prefixTlv;
-    const BorderRouterTlv *brSubTlv;
-
-    VerifyOrExit(BorderRouter::RoutingManager::IsValidOmrPrefix(aPrefix));
-
-    prefixTlv = FindPrefix(aPrefix);
-    VerifyOrExit(prefixTlv != nullptr);
-
-    brSubTlv = prefixTlv->FindSubTlv<BorderRouterTlv>(/* aStable */ true);
-
-    VerifyOrExit(brSubTlv != nullptr);
-
-    for (const BorderRouterEntry *entry = brSubTlv->GetFirstEntry(); entry <= brSubTlv->GetLastEntry(); entry++)
-    {
-        OnMeshPrefixConfig config;
-
-        config.SetFrom(*prefixTlv, *brSubTlv, *entry);
-
-        if (BorderRouter::RoutingManager::IsValidOmrPrefix(config))
-        {
-            ExitNow(contains = true);
-        }
-    }
-
-exit:
-    return contains;
-}
-
-#endif // OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
-
 //---------------------------------------------------------------------------------------------------------------------
 // Leader::ContextIds