The overall European e-cigarette market could have reached £1.3bn last year – almost double what was previously thought.
The new figure comes from a more in-depth study and analysis from ECigIntelligence which used a based its calculations on a different research.
The analysis from ECigIntelligence claims that the previous research over-valued some national markets and underestimated others.
Early figures had suggested that the European e-cigarette market was worth somewhere in the $1.2bn (£0.7bn, €0.9bn) ballpark.
ECigIntelligence managing director Tim Phillips said: "We took a conservative approach when performing our market analysis, but we still found the European market to be significantly larger than expected. This highlights the startling potential of the e-cigarette sector.
"Our report marks the culmination of months of research and sets the standard of quality reporting that can be expected from ECigIntelligence."
Barnaby Page, ECigIntelligence editorial director, added: "These figures show that e-cigarettes are here to stay - the question now is who will dominate one of the fastest-growing FMCG markets in Europe."
EcigIntelligence expects the e-cigarette market to be transformed by the EU's Tobacco Products Directive – a new set of regulations that govern the tobacco industry set to be in full force by 2016 – "but not destroy it".
Advertising of e-cigarettes is going to be a bit of a sticky topic under the new regulations with flavours and refillable products items that will be affected by the regulations.
As it stands, the UK and Germany have the most e-cigarette users, with Poland also possessing a substantial market.
Tobacco sales in the UK in 2012 amounted to an estimated £15.1bn but some quarters are hoping that the e-cigarette will move to replace standard cigarettes, although manufacturers of 'vapours' are being discouraged to market it as a replacement as they would need a licence to do so.
Others are however worried about the long-term health implications of e-cigarettes as tests into its health impacts over a substantial period are yet to be completed.