diff --git a/deepdiff/search.py b/deepdiff/search.py
index 9b1b11a1..ab081f6d 100644
--- a/deepdiff/search.py
+++ b/deepdiff/search.py
@@ -106,7 +106,7 @@ def __init__(self,
 
         self.obj: Any = obj
         self.case_sensitive: bool = case_sensitive if isinstance(item, strings) else True
-        item = item if self.case_sensitive else (item.lower() if isinstance(item, str) else item)
+        item = item if self.case_sensitive or use_regexp else (item.lower() if isinstance(item, str) else item)
         _exclude_exact, self.exclude_glob_paths = separate_wildcard_and_exact_paths(set(exclude_paths) if exclude_paths else None)
         self.exclude_paths: SetOrdered = SetOrdered(_exclude_exact) if _exclude_exact else SetOrdered()
         self.exclude_regex_paths: List[Pattern[str]] = [re.compile(exclude_regex_path) for exclude_regex_path in exclude_regex_paths]
@@ -127,7 +127,8 @@ def __init__(self,
             item = str(item)
         if self.use_regexp:
             try:
-                item = re.compile(item)
+                flags = 0 if self.case_sensitive else re.IGNORECASE
+                item = re.compile(item, flags=flags)
             except TypeError as e:
                 raise TypeError(f"The passed item of {item} is not usable for regex: {e}") from None
         self.strict_checking: bool = strict_checking
@@ -236,7 +237,7 @@ def __search_dict(self,
             parents_ids_added = add_to_frozen_set(parents_ids, item_id)
 
             new_parent = parent_text % (parent, item_key_str)
-            new_parent_cased = new_parent if self.case_sensitive else new_parent.lower()
+            new_parent_cased = new_parent if self.case_sensitive or self.use_regexp else new_parent.lower()
 
             str_item = str(item)
             if (self.match_string and str_item == new_parent_cased) or\
@@ -282,7 +283,10 @@ def __search_iterable(self,
 
     def __search_str(self, obj: Union[str, bytes, memoryview], item: Union[str, bytes, memoryview, Pattern[str]], parent: str) -> None:
         """Compare strings"""
-        obj_text = obj if self.case_sensitive else (obj.lower() if isinstance(obj, str) else obj)
+        obj_text = (
+            obj if self.case_sensitive or self.use_regexp
+            else (obj.lower() if isinstance(obj, str) else obj)
+        )
 
         is_matched = False
         if self.use_regexp and isinstance(item, type(re.compile(''))):
diff --git a/tests/test_search.py b/tests/test_search.py
index 3984349a..78451296 100644
--- a/tests/test_search.py
+++ b/tests/test_search.py
@@ -2,6 +2,7 @@
 import pytest
 import ipaddress
 import logging
+import re
 from typing import Union
 from deepdiff import DeepSearch, grep
 from datetime import datetime
@@ -369,6 +370,49 @@ def test_regex_in_string(self):
         result = {"matched_values": {"root"}}
         assert DeepSearch(obj, item, verbose_level=1, use_regexp=True) == result
 
+    @pytest.mark.parametrize('pattern, values, indexes', [
+        (r'\S+', ['word', '   '], [0]),
+        (r'\W+', ['word', '---'], [1]),
+        (r'\D+', ['123', 'letters'], [1]),
+        (r'\N{LATIN CAPITAL LETTER A}', ['a', 'A', 'b'], [0, 1]),
+        (r'\U0001F680', ['rocket', '\U0001F680'], [1]),
+        (r'(?-i:ABC)', ['ABC', 'abc'], [0]),
+        (r'(?-i:ABC)def', ['ABCdef', 'ABCDEF', 'abcdef'], [0, 1]),
+    ])
+    def test_case_insensitive_regex_preserves_syntax(self, pattern, values, indexes):
+        expected = {'matched_values': {f'root[{index}]': values[index] for index in indexes}}
+        assert DeepSearch(values, pattern, use_regexp=True, verbose_level=2) == expected
+
+    @pytest.mark.parametrize('case_sensitive, indexes', [(False, [0, 1]), (True, [0])])
+    def test_regex_case_sensitivity(self, case_sensitive, indexes):
+        values = ['ABC', 'abc', 'other']
+        expected = {'matched_values': {f'root[{index}]': values[index] for index in indexes}}
+        assert DeepSearch(values, 'ABC', use_regexp=True, case_sensitive=case_sensitive, verbose_level=2) == expected
+
+    @pytest.mark.parametrize('pattern, keys', [
+        (r"\['\D+'\]$", ['Name', 'name']),
+        (r"\['(?-i:Name)'\]$", ['Name']),
+        (r"\['name'\]$", ['Name', 'name']),
+    ])
+    def test_case_insensitive_regex_preserves_dictionary_paths(self, pattern, keys):
+        obj = {'Name': 1, 'name': 2, '123': 3}
+        expected = {'matched_paths': {f"root['{key}']": obj[key] for key in keys}}
+        assert DeepSearch(obj, pattern, use_regexp=True, verbose_level=2) == expected
+
+    @pytest.mark.parametrize('flags, indexes', [(0, [0]), (re.IGNORECASE, [0, 1])])
+    def test_compiled_regex_keeps_its_flags(self, flags, indexes):
+        values = ['ABC', 'abc']
+        expected = {'matched_values': {f'root[{index}]': values[index] for index in indexes}}
+        assert DeepSearch(values, re.compile('ABC', flags), use_regexp=True, verbose_level=2) == expected
+
+    @pytest.mark.parametrize('case_sensitive, expected', [
+        (False, {'matched_values': {'root[0]': r'\D+', 'root[1]': r'\d+'}}),
+        (True, {'matched_values': {'root[0]': r'\D+'}}),
+    ])
+    def test_literal_search_keeps_case_handling(self, case_sensitive, expected):
+        values = [r'\D+', r'\d+', '123']
+        assert DeepSearch(values, r'\D+', case_sensitive=case_sensitive, verbose_level=2) == expected
+
     def test_regex_does_not_match_the_regex_string_itself(self):
         obj = ["We like python", "but not (?:p|t)ython"]
         item = "(?:p|t)ython"