A British arms manufacturer became the latest company to stop selling equipment to Turkey after its components were found in drones shot down during the Nagorno-Karabakh conflict.
Turkey has come under scrutiny for using advanced weaponry, including deadly Bayraktar drones, in support of Azerbaijan in the recent conflict with Armenia. Scores of Armenian civilians are thought to have been killed in strikes by Turkish-supplied Azeri forces.
Andair, a British defence company in Portsmouth, was approached by the Armenian embassy requesting it stop supplies because its valve parts were being used in the fuel pumps for the armed drones made by Baykar Defence in Istanbul.
"After the investigation it was apparent that this was the case and Andair immediately halted supply and cancelled all orders from Baykar," the company said.
Turkey used its Bayraktar TB2 drones to help what is regarded as a successful Azerbaijan offensive in the six-week war that began in September last year. More than 100 Armenian civilians were killed and 3,200 Armenian troops
The Bayraktar drone was developed in Turkey, partly using components from western countries, and can fly 24 hours non-stop, using its surveillance equipment to conduct precision-strike missions with thermobaric missiles. Each drone costs about $5 million (Dh18.4m) and they have proved effective at destroying tanks and infantry in Libya, Syria and against Kurdish civilians and fighters.
During the conflict, Azerbaijan's President Ilham Aliyev boasted that the UAVs had reduced his casualties. "These drones show Turkey's strength" and "empower Azerbaijanis", he said.
Tim Ripley, a defence analyst for Jane's Defence Weekly, said Andair's actions meant that defence companies now had to realise that Turkey, under the leadership of Recep Tayyip Erdogan, was ready to engage outside the country's border in conflicts under uncertain legal circumstances.
"Western countries are facing up to the reality that Turkey is potentially a rogue state that should not be supplied with arms. Both the French and Americans have given up on them and we're waiting to see what other countries do," he said.
"Defence companies should therefore be very cautious to ensure that they have all their 'end user certificates' documents certified by their national governments because it might come back to bite them."
British defence company sources said firms would be nervous about component sales to Turkey. "We have to be much more careful than we were in the past about where seemingly innocuous parts actually end up and there is a considerable degree of nervousness in Western Europe about this topic at the moment," said a defence company director. "It's only going to grow in the future because of the potential for companies to be linked to human rights abuses."
He said that given Turkey's involvement in several conflicts around the region its "belligerent positioning makes people very twitchy". While in past years Turkey has been a reliable Nato partner "it has now drifted into the arms of more strident people, which has caused a degree of anxiety for politicians and the military".
Andair's decision will mean that Baykar will now make components locally, which could lead to a delay in manufacture of the estimated 24 Bayraktar drones it builds each year. "There may be a slight interruption to the production chain but it's not going to impact the Turkish Air Force now, although maybe next year," Mr Ripley said.
European governments in upcoming summits are now expected to further restrict arms sales to Turkey. "They will need legislation as they are going to have to do more to tighten up sales because this can be an embarrassment to western governments," said the defence company director.