diff --git a/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_scan.c b/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_scan.c
index 710ef8f620cd7..5f51c55f4255d 100644
--- a/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_scan.c
+++ b/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_scan.c
@@ -1089,6 +1089,9 @@ static void isr_done_cleanup(void *param)
 		lll->is_stop = 1U;
 	}
 
+	/* LLL scheduled auxiliary PDU reception is_abort on duration expire or
+	 * aborted in the unreserved time space.
+	 */
 	if (lll->is_aux_sched) {
 		struct node_rx_pdu *node_rx2;
 
diff --git a/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_sync.c b/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_sync.c
index 7fa1f66f4ddfe..c80591939b1ce 100644
--- a/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_sync.c
+++ b/subsys/bluetooth/controller/ll_sw/nordic/lll/lll_sync.c
@@ -635,9 +635,6 @@ static void abort_cb(struct lll_prepare_param *prepare_param, void *param)
 	lll = prepare_param->param;
 	lll->skip_prepare += (lll->lazy_prepare + 1U);
 
-	/* Reset Sync context association with any Aux context as the chain reception is aborted. */
-	lll->lll_aux = NULL;
-
 	/* Extra done event, to check sync lost */
 	e = ull_event_done_extra_get();
 	LL_ASSERT(e);
@@ -817,11 +814,6 @@ static int isr_rx(struct lll_sync *lll, uint8_t node_type, uint8_t crc_ok,
 		 * again a node_rx for periodic report incomplete.
 		 */
 		if (node_type != NODE_RX_TYPE_EXT_AUX_REPORT) {
-			/* Reset Sync context association with any Aux context
-			 * as a new chain is being setup for reception here.
-			 */
-			lll->lll_aux = NULL;
-
 			node_rx = ull_pdu_rx_alloc_peek(4);
 		} else {
 			node_rx = ull_pdu_rx_alloc_peek(3);
@@ -1189,7 +1181,11 @@ static void isr_rx_done_cleanup(struct lll_sync *lll, uint8_t crc_ok, bool sync_
 {
 	struct event_done_extra *e;
 
-	/* Reset Sync context association with any Aux context as the chain reception is done. */
+	/* Reset Sync context association with any Aux context as the chain reception is done.
+	 * By code inspection there should not be a race that ULL execution context assigns lll_aux
+	 * that would be reset here, because either we are here not receiving a chain PDU or the
+	 * lll_aux has been set in the node rx type NODE_RX_TYPE_EXT_AUX_RELEASE before we are here.
+	 */
 	lll->lll_aux = NULL;
 
 	/* Calculate and place the drift information in done event */
diff --git a/subsys/bluetooth/controller/ll_sw/ull_scan_aux.c b/subsys/bluetooth/controller/ll_sw/ull_scan_aux.c
index 7de4c201768dc..7419325254a8b 100644
--- a/subsys/bluetooth/controller/ll_sw/ull_scan_aux.c
+++ b/subsys/bluetooth/controller/ll_sw/ull_scan_aux.c
@@ -1126,6 +1126,10 @@ void ull_scan_aux_release(memq_link_t *link, struct node_rx_pdu *rx)
 	param_ull = HDR_LLL2ULL(rx->rx_ftr.param);
 
 	if (ull_scan_is_valid_get(param_ull)) {
+		/* Release aux context when LLL scheduled auxiliary PDU
+		 * reception is_abort on duration expire or aborted in the
+		 * unreserved time space.
+		 */
 		struct lll_scan *lll;
 
 		/* Mark for buffer for release */
@@ -1134,8 +1138,21 @@ void ull_scan_aux_release(memq_link_t *link, struct node_rx_pdu *rx)
 		lll = rx->rx_ftr.param;
 		lll_aux = rx->rx_ftr.lll_aux;
 
+		/* Under race condition when LLL scheduling a reception of
+		 * auxiliary PDU, a scan aux context may be assigned late and
+		 * the node rx releasing the aux context will not have it.
+		 * Release the scan aux context assigned in the scan context.
+		 */
+		if (!lll_aux) {
+			lll_aux = lll->lll_aux;
+		}
+
 	} else if (!IS_ENABLED(CONFIG_BT_CTLR_SYNC_PERIODIC) ||
 		   ull_scan_aux_is_valid_get(param_ull)) {
+		/* Release aux context when ULL scheduled auxiliary PDU
+		 * reception is aborted.
+		 */
+
 		/* Mark for buffer for release */
 		rx->hdr.type = NODE_RX_TYPE_RELEASE;
 
@@ -1150,9 +1167,21 @@ void ull_scan_aux_release(memq_link_t *link, struct node_rx_pdu *rx)
 		/* reset data len total */
 		sync->data_len = 0U;
 
+		/* Release aux context in case of chain PDU reception, otherwise
+		 * lll_aux is NULL.
+		 */
 		lll = rx->rx_ftr.param;
 		lll_aux = rx->rx_ftr.lll_aux;
 
+		/* Under race condition when LLL scheduling a reception of
+		 * auxiliary PDU, a scan aux context may be assigned late and
+		 * the node rx releasing the aux context will not have it.
+		 * Release the scan aux context assigned in the sync context.
+		 */
+		if (!lll_aux) {
+			lll_aux = lll->lll_aux;
+		}
+
 		/* Change node type so HCI can dispatch report for truncated
 		 * data properly.
 		 */
@@ -1183,13 +1212,16 @@ void ull_scan_aux_release(memq_link_t *link, struct node_rx_pdu *rx)
 		scan = ull_scan_is_valid_get(scan);
 		if (scan) {
 			is_stop = scan->is_stop;
-		} else {
+		} else if (IS_ENABLED(CONFIG_BT_CTLR_SYNC_PERIODIC)) {
 			struct lll_sync *sync_lll;
 			struct ll_sync_set *sync;
 
 			sync_lll = (void *)lll;
 			sync = HDR_LLL2ULL(sync_lll);
 			is_stop = sync->is_stop;
+		} else {
+			LL_ASSERT(0);
+			return;
 		}
 
 		if (!is_stop) {