Getting a 401 Error when trying to DELETE

PornStarsList
@PornStarsList Porn Stars List

Hi
I am authenticating on every API call apart from DELETE.
Can anyone shed some light on why this code I use for all my other applications fails on a 401 error when trying to unfollow somone. Using the same method to pull in followers, tweets etc is working great.

<?php

require '../include/tmhOAuth.php';
require '../include/tmhUtilities.php';
$tmhOAuth = new tmhOAuth(array(
'consumer_key' => '***HIDDEN******',
'consumer_secret' => '***HIDDEN******',
'user_token' => '***HIDDEN******',
'user_secret' => '***HIDDEN******',
));

$user_id = 13;
$tmhOAuth->request('DELETE', $tmhOAuth->url('1/friendships/destroy'), array(
'user_id' => $user_id
));

echo $tmhOAuth->response['code'];

?>

5 days 16 hours ago