Iceland’s Keflavik airbase, a bulwark of western security during the cold war, would be home to two squadrons of Russian-made fighter jets under plans being considered by the Icelandic government.

Reykjavik is in talks about renting the airbase to a private company that says it is buying up to €1.2bn ($1.5bn) of Sukhoi warplanes from Belarus for use as a mock enemy in military training exercises.

ECA Program says it has already signed up five air forces keen to test their pilots and jets against an aircraft most commonly flown by the Russian and Chinese militaries.

“We are the car rental service of the military training world,” said Melville ten Cate, ECA’s Dutch co-founder.

According to Mr Ten Cate, ECA has agreed to buy 15 Sukhoi Su-27 “Flanker” jets from BelTechExport, a Belarusian arms export company, with the option of 18 more. If completed, it would be the biggest sale of fighter aircraft to a private buyer and the first large-scale import of Russian-made warplanes into a Nato country.

Iceland’s government has so far taken ECA seriously – so much so that some of the end-user certificates needed to import the jets have already been issued, according to officials.

One official said the government was close to giving conditional approval to ECA. Reykjavik would consult Nato allies before a final go-ahead, he added. Yet, much about the deal is shrouded in mystery and several defence industry officials have questioned its credibility – including some that Mr Ten Cate says are involved.

BelTechExport yesterday denied knowledge of the deal, having previously confirmed it to the Financial Times. An official at the Belarusian agency responsible for approving arms exports said he was not aware of it and Rosoboronexport, the Russian state arms exporter, denied involvement.