The Turkish authorities have postponed a visit to Turkey next month by Swiss Economics Minister Joseph Deiss.
They have cited agenda problems of his Turkish counterpart, although it is widely considered in Switzerland that the real cause for the postponement is the Armenian genocide issue.
It is the second time that Ankara has made such a delaying move. In September 2003, Turkish authorities cancelled a visit by the Swiss foreign minister, Micheline Calmy-Rey. She eventually visited the country in March.
The Swiss authorities confirmed reports in Friday’s edition of the Zurich newspaper Tages Anzeiger and Geneva’s Le Temps that Switzerland’s ambassador to Turkey had received an official note cancelling Deiss’s trip.
It said that the Turkish economics minister, Kürsad Tüzmen, was unavailable on the dates that had been pencilled in. As a result the planned trip could not take place in September.
However the Turkish embassy in Bern said the visit had only been postponed and denied any link to a criminal investigation into a Turkish party leader in Switzerland.
"Mr Deiss's visit is to be worked out through mutual contacts on both sides in the period ahead," Sibel Gal, press attaché at the Turkish embassy, told swissinfo.
The snub is the latest episode in tensions between Ankara and Bern, provoked indirectly by the commemoration two weeks ago of the 1923 Treaty of Lausanne, which defined the borders of modern Turkey.
Ankara has criticised Swiss authorities for opening an investigation into Doğu Perinçek, head of the Turkish Workers’ Party who denied the Armenian genocide at a news conference in canton Zurich.
Under Swiss law, any act of denying, belittling or justifying genocide is a violation of the country’s anti-racism laws.
Perinçek, who appeared before the public prosecutor of Winterhur, is also the subject of investigation for the same reason in canton Vaud.
A similar investigation in Winterthur has been opened in the case of Turkish historian Yusuf Halaçoğlu.
The Turkish government, which has strongly condemned the Swiss action, considers that the investigations are contrary to international law and has demanded they be stopped.
In a diplomatic spat, the ambassador of Switzerland in Turkey was last week summoned to explain Switzerland’s position, while Turkey’s envoy in Bern visited the Swiss foreign ministry a day later.
The Swiss economics ministry has expressed regret at Ankara’s decision, hoping that the visit could take place at a later date.
The trip was a working visit with a delegation of Swiss business leaders. Such trips take place about once every four years with countries that represent an important market for Switzerland.
The ministry commented that if the real reason for the postponement were due to the investigations it would regret that because Switzerland practised "the separation of powers which is an essential value of its democracy".
The House of Representatives is the only federal institution that has officially recognised genocide against the Armenians.
The historical interpretation of the death or deportation of between 800,000 and 1.8 million Armenians between 1915 and 1919 has caused tensions between Turkey and many European countries.
Armenian genocide has been recognised by the parliaments of several countries, including France, Russia and Italy.
The UN recognised it in 1985, two years after the European Parliament.
The Swiss House of Representatives followed suit in 2003.
The Swiss government does not officially speak of "genocide", but of "mass deportation" and "massacre".
Tensions have escalated once again between Turkey and Switzerland, with the cancellation of the planned trip by Swiss Economics Minister Joseph Deiss in September.
Turkey is upset at the questioning of a Turkish politician suspected of having violated Swiss anti-racism laws.
During meetings in Switzerland, Doğu Perinçek offered revisionist views about the Armenian genocide.