Custom post query with pagination

<?php
  $temp = $wp_query;
  $wp_query = null;
  $wp_query = new WP_Query();
  $wp_query->query('showposts=6&post_type=consultant-items'.'&paged='.$paged);

  while ($wp_query->have_posts()) : $wp_query->the_post();
?>

<?php
    $consultant_pic = get_post_meta($post->ID, 'consultant_pic', true);
?>

<div class="single_consultant">
    <img src="<?php echo $consultant_pic; ?>" alt="" />
    <?php the_content(); ?>
</div>


<?php endwhile; ?>

<?php if (function_exists('wp_pagenavi')) { wp_pagenavi(); } else { include('navigation.php'); } ?>

<?php
  $wp_query = null;
  $wp_query = $temp;  // Reset
?>