I can not see LEADID in tasks of API

https://crm.zoho.com/crm/private/xml/Tasks/getRecordById?authtoken=[authtoken]&scope=crmapi&id=615130000010740347

  <response uri="/crm/private/xml/Tasks/getRecordById">
 

     
     <result>
    
        <Tasks>
       
           <row no="1">
          
            <FL val="ACTIVITYID">
            615130000010740347</FL>
           
            <FL val="SMOWNERID">
            639130000001901075
            </FL>
           
              <FL val="Task Owner">
             
               <![CDATA[ Gabino ]]>
              
              </FL>
             
              <FL val="Subject">
             
                 <![CDATA[
                
                 RELATION
                
                 ]]>
                
              </FL>
             
              <FL val="Due Date">
             
               <![CDATA[ 2016-06-25 ]]>
              
              </FL>
             
              <FL val="Status">
             
               <![CDATA[ No iniciado ]]>
              
              </FL>
             
              <FL val="Priority">
             
               <![CDATA[ Normal ]]>
              
              </FL>
             
            <FL val="SMCREATORID">
            639130000001901075</FL>
           
              <FL val="Created By">
             
               <![CDATA[ Gabino]]>
              
              </FL>
             
            <FL val="MODIFIEDBY">639130000001901075</FL>
           
              <FL val="Modified By">
             
               <![CDATA[ Gabino]]>
              
              </FL>
             
              <FL val="Created Time">
             
               <![CDATA[ 2016-05-25 13:18:05 ]]>
              
              </FL>
             
              <FL val="Modified Time">
             
               <![CDATA[ 2016-05-25 13:18:05 ]]>
              
              </FL>
             
           </row>
          
        </Tasks>
       
     </result>

  </response>
 

I cant see the field LEADID and it is associate with a Lead.

Why it will be?

Thanks