Lucene ignores language filters

Lucene plugin is ignoring language filters and returns all translated documents in a wiki on a blank search.

XE 2.5.1
rebuilt index

#set($searchResults = $xwiki.lucene.getSearchResults('wiki:"xwiki" AND name:"WebHome" AND space:"Main"', "", "default,en"))
#set($items = $searchResults.getResults(0, 0))
$searchResults.getHitcount()
$searchResults.getTotalHitcount()
#foreach($item in $items)
  * ${item.id} | ${item.score} | ${item.fullName} | ${item.language}
#end

Returned results are:
13
13

• xwiki:Main.WebHome.default | 1.0 | Main.WebHome | default
• xwiki:Main.WebHome.zh_TW | 0.48720846 | Main.WebHome | zh_TW
• xwiki:Main.WebHome.ca | 0.48720846 | Main.WebHome | ca
• xwiki:Main.WebHome.de | 0.48720846 | Main.WebHome | de
• xwiki:Main.WebHome.es | 0.48720846 | Main.WebHome | es
• xwiki:Main.WebHome.fr | 0.48720846 | Main.WebHome | fr
• xwiki:Main.WebHome.it | 0.48720846 | Main.WebHome | it
• xwiki:Main.WebHome.lv | 0.48720846 | Main.WebHome | lv
• xwiki:Main.WebHome.nl | 0.48720846 | Main.WebHome | nl
• xwiki:Main.WebHome.ro | 0.48720846 | Main.WebHome | ro
• xwiki:Main.WebHome.sv | 0.48720846 | Main.WebHome | sv
• xwiki:Main.WebHome.uk | 0.48720846 | Main.WebHome | uk
• xwiki:Main.WebHome.zh | 0.48720846 | Main.WebHome | zh

It seems that language filters are ignored.