Possible Clues:

• It's just a rumour that there's an addition inside one of the pack
• The French might be able to duck such a rumour
• There's a rumour that one made a duck in France
• False rumour also from France
• Jack perhaps came across an inaccurate rumour
• A false rumour from France? (6)
• A false rumour or story from France
• Don't believe it
• Fabricated report
• A false story or rumour