[Orgmode] How to add comments in a plain list

[René]

Is there a way to insert comments in a plain list without breaking it into two
distinct lists?

Such a list:

 1. first
 2. second
 # comment about second item
 3. third
 4. fourth

is actually considered as

 1. first
 2. second
 # comment about second item
 1. third
 2. fourth