The escalating alcohol levels in Bordeaux wine could see the region lose its character, according to an expert.

Top oenologist and owner of the Chateau Leoville Poyferre estate in St Julien, Didier Cuvelier, says it is now common to see the Merlot wines pass 15 per cent alcoholic content, Decanter reports.

Mr Cuvelier said this is a "disturbing development" that threatens to consign the traditional Bordeaux style to the past.

He told the publication that critical demand for greater concentration is leading to later and later harvesting, making controlling alcohol levels a challenge.

"I have been a consultant for 30 years. I have spent the first 20 years telling people not to harvest too early; in the last ten years I have told them not to harvest too late," Mr Cuvalier explained.

Michel Rolland export manager Pascal Fricard recently suggested that Bordeaux needs to consider introducing non-native grapes.

Smaller vineyards in the region need to be able to diversify, in order to compete with the larger First Growth estates, Mr Fricard believes.