diff --git a/zarr/storage.py b/zarr/storage.py
index f6903d29b2..2d717b68a8 100644
--- a/zarr/storage.py
+++ b/zarr/storage.py
@@ -1831,7 +1831,12 @@ def __exit__(self, *args):
     def __getitem__(self, key):
         with self.mutex:
             with self.zf.open(key) as f:  # will raise KeyError
-                return f.read()
+                data = f.read()
+
+                if data:
+                    return data
+                else:
+                    raise KeyError("Key not found")
 
     def __setitem__(self, key, value):
         if self.mode == "r":
@@ -1852,7 +1857,23 @@ def __setitem__(self, key, value):
             self.zf.writestr(keyinfo, value)
 
     def __delitem__(self, key):
-        raise NotImplementedError
+        with self.mutex:
+            try:
+                self.zf.getinfo(key)
+            except KeyError:
+                raise KeyError("Cannot delete a non-existent key")
+            keyinfo = zipfile.ZipInfo(
+                filename=key,
+                date_time=time.localtime(time.time())[:6]
+            )
+            keyinfo.compress_type = self.compression
+            if keyinfo.filename[-1] == os.sep:
+                keyinfo.external_attr = 0o40775 << 16   # drwxrwxr-x
+                keyinfo.external_attr |= 0x10           # MS-DOS directory flag
+            else:
+                keyinfo.external_attr = 0o644 << 16     # ?rw-r--r--
+
+            self.zf.writestr(keyinfo, b"")
 
     def __eq__(self, other):
         return (
@@ -1864,7 +1885,8 @@ def __eq__(self, other):
 
     def keylist(self):
         with self.mutex:
-            return sorted(self.zf.namelist())
+            namelist = [key for key in self.zf.namelist() if self.zf.getinfo(key) != b""]
+            return sorted(namelist)
 
     def keys(self):
         yield from self.keylist()
@@ -1878,7 +1900,11 @@ def __len__(self):
     def __contains__(self, key):
         try:
             with self.mutex:
-                self.zf.getinfo(key)
+                value = self.zf.getinfo(key)
+
+                if value == b"":
+                    raise KeyError
+
         except KeyError:
             return False
         else:
diff --git a/zarr/tests/test_storage.py b/zarr/tests/test_storage.py
index 358d043ad6..797feb945e 100644
--- a/zarr/tests/test_storage.py
+++ b/zarr/tests/test_storage.py
@@ -217,6 +217,21 @@ def test_pop(self):
 
         store.close()
 
+    def test_delitem(self):
+        store = self.create_store()
+        foo = self.root + 'foo'
+        store[foo] = b'bar'
+
+        del store[foo]
+
+        with pytest.raises(KeyError):
+            store[foo]
+        # if foo in store:
+        # if isinstance(store, ZipStore):
+        #     assert store[foo] == b''
+        # else:
+        #     assert foo not in store
+
     def test_popitem(self):
         store = self.create_store()
         store[self.root + "foo"] = b"bar"
@@ -1803,8 +1818,7 @@ def test_flush(self):
         store.flush()
         assert store[self.root + "foo"] == b"bar"
         store.close()
-
-        store = self.ZipStoreClass("data/store.zip", mode="r")
+        store = self.ZipStoreClass('data/store.zip', mode='r')
         store.flush()  # no-op
 
     def test_context_manager(self):
@@ -1816,9 +1830,9 @@ def test_context_manager(self):
     def test_pop(self):
         # override because not implemented
         store = self.create_store()
-        store[self.root + "foo"] = b"bar"
-        with pytest.raises(NotImplementedError):
-            store.pop(self.root + "foo")
+        store[self.root + 'foo'] = b'bar'
+        store.pop(self.root + 'foo')
+        assert store[self.root + 'foo'] == b""
 
     def test_popitem(self):
         # override because not implemented