wp_insert_post fails to add comment_count

I am running the following piece of code (assume all variables have values) is a custom importer that I am trying for Joomla2Wordpress.

$ret_id = wp_insert_post(array(
		'ID'			=> $pinfo,
		'post_date'		=> $Posted,
		'post_date_gmt'		=> $post_date_gmt,
		'post_author'		=> $authorid,
		'post_modified'		=> $LastMod,
		'post_modified_gmt' => $post_modified_gmt,
		'post_title'		=> $Title,
		'post_content'		=> $Body,
		'post_excerpt'		=> $Excerpt,
		'post_status'		=> $post_status,
		'post_name'		=> $sefurl,
		'comment_count'		=> $comments_count)
	);

However while the code inserts post correctly, the comments count is not updated (remains zero). The codex page doesn’t mention the parameter at all.

Can anybody help?