Index: src/main/java/org/xwiki/officeimporter/internal/builder/DefaultXHTMLOfficeDocumentBuilder.java
===================================================================
--- src/main/java/org/xwiki/officeimporter/internal/builder/DefaultXHTMLOfficeDocumentBuilder.java	(revision 25281)
+++ src/main/java/org/xwiki/officeimporter/internal/builder/DefaultXHTMLOfficeDocumentBuilder.java	(working copy)
@@ -23,6 +23,7 @@
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.UnsupportedEncodingException;
+import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -92,6 +93,11 @@
         HTMLCleanerConfiguration configuration = this.ooHtmlCleaner.getDefaultConfiguration();
         configuration.setParameters(params);
         Document xhtmlDoc = this.ooHtmlCleaner.clean(reader, configuration);
+        try {
+            reader.close();            
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
         
         // Return a new XHTMLOfficeDocument instance.
         return new XHTMLOfficeDocument(xhtmlDoc, artifacts);
Index: src/main/java/org/xwiki/officeimporter/internal/openoffice/DefaultOpenOfficeDocumentConverter.java
===================================================================
--- src/main/java/org/xwiki/officeimporter/internal/openoffice/DefaultOpenOfficeDocumentConverter.java	(revision 25281)
+++ src/main/java/org/xwiki/officeimporter/internal/openoffice/DefaultOpenOfficeDocumentConverter.java	(working copy)
@@ -191,6 +191,7 @@
                 }
                 result.put(artifact.getName(), bos.toByteArray());
                 bos.reset();
+                fis.close();
             } catch (IOException ex) {
                 getLogger().error(String.format(ERROR_READING_ARTIFACT, artifact.getName()), ex);
                 // Skip the artifact.