diff --git a/htdocs/categories/class/categorie.class.php b/htdocs/categories/class/categorie.class.php
index 9f4be55eb40..7e990e602c9 100644
--- a/htdocs/categories/class/categorie.class.php
+++ b/htdocs/categories/class/categorie.class.php
@@ -571,6 +571,48 @@ class Categorie
 		}
 	}
 
+	/**
+	 * check for the presence of an object in a category
+	 * @param string $type              object type
+	 * @param int    $object_id         id of the object to search
+	 * @return int   nb                 number of occurrences
+	 */
+	function containsObject($type, $object_id)
+	{
+		$field = ''; $classname = ''; $category_table = ''; $object_table = '';
+		if ($type == 'product') {
+			$field = 'product';
+		}
+		if ($type == 'customer') {
+			$field = 'societe';
+		}
+		if ($type == 'supplier') {
+			$field = 'societe';
+			$category_table = 'fournisseur';
+		}
+		if ($type == 'member') {
+			$field = 'member';
+			$category_table = '';
+		}
+		if ($type == 'contact') {
+			$field = 'socpeople';
+			$category_table = 'contact';
+		}
+		if (empty($category_table)) {
+			$category_table = $field;
+		}
+		$sql = "SELECT COUNT(*) as nb FROM " . MAIN_DB_PREFIX . "categorie_" . $category_table;
+		$sql .= " WHERE fk_categorie = " . $this->id . " AND fk_" . $field . " = " . $object_id;
+		dol_syslog(get_class($this)."::containsObject sql=".$sql);
+		$resql = $this->db->query($sql);
+		if ($resql) {
+			return $this->db->fetch_object($resql)->nb;
+		} else {
+			$this->error=$this->db->error().' sql='.$sql;
+			dol_syslog(get_class($this)."::containsObject ".$this->error, LOG_ERR);
+			return -1;
+		}
+	}
 
 	/**
 	 * Return childs of a category