htaccess 301 – Folder named a number remains in redirected URL

I am redirecting a bunch of URL’s in htaccess

I have an issue where if the URL to be redirected has a folder named a number that folder remains in the redirected uRL

eg:
redirecting: /index.php/news/15/rhs to http://www.domain.com/news/rhs/ ends up as http://www.domain.com/news/15/rhs/

I dont want the /15/ in the final URL

All other redirects that don’t contain folders named numbers work fine.

The new site is WordPress and current mod_rewrite is:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

Any help greatly appreciated.