Get related fields and values

Hey guys. We need help.

We have created a costum module Properties, wich has a many to many relationship to the module Leads. Now we are looking for a method to get the leads with there properties together through the API.

With this code we get only the properties ids and there names but without there related leads. The relationship_list ist always empty.

$get_entry_list_parameters = array(
'session' => $this->sessionId,
'module_name' => 'Leads',
'module_id' => 'ba52a333-9082-d114-170a-54c108a9366e',
'link_field_name' => 'prop_eigenschaft_leads',
'related_module_query' => '',
'related_fields' => array(
'id',
'name',
),
'related_module_link_name_to_fields_array' => array(
"prop_eigenschaft_leadsleads_idb"=>array(

'name',
'id',
),

),

'deleted'=> '0',
'order by' => "",
'offset' => '0',
);

$results = $this->call('get_relationships', $get_entry_list_parameters, $this->apiUrl);