Prevent LF adding in XML file while converting

Question

I use PHP to convert XML into XML.

While the conversion operates nicely, I have LF that appears after HTML tags. ie:

The weather was <i>nice</i> and Eve was feeling lucky. 

becomes

The weather was <i>nice</i>**LF**

and Eve was feeling lucky.

Does anyone has any idea where it could come from?

The code :

case 'Texte':
$this->setData('body', $domElement);