Controls were restored
After having an interview with the Captain the spokeswoman has now changed the report about the incident: the controls were jammed indeed (co-pilot flying), but after breaking the connection between the two control columns the captains yoke did work properly and the landing was carried out with full control. She also said, that her reports of earlier today, that the pilots landed while steering on engines, were premature and based on collegue's report from Graz.
Simon