British Airways has delayed the resumption of flights between London and Tehran until September.
The carrier had announced plans to launch a six-times weekly service to the Iranian capital from July 14, a return to the city after a gap of four years.
But industry website airlineroute.net has reported that the relaunch has been delayed until September 1, and BA's online reservation system is now showing no flights until the start of September.
And a spokesperson for British Airways has now confirmed the delay:
"Tehran is an important route for British Airways and we are keen to ensure that the service we offer meets the high levels customers rightly expect from day one.
"While preparations for the new route have generally been progressing well, some technical issues have arisen which make it sensible for us to put back the launch of flights from mid-July to September 1, 2016."
The service from Heathrow Terminal 5 will be operated by a four-class B777.
British Airways first flew between London and the Iranian capital in 1946.