Doany, 35, who has lived in the US for the past 15 years, last called his mother on Sunday following a business trip to Britain.

Officials said Doany remains unaccounted for while three other Jordanians who were in the same building at the time of the strike escaped the fire that led to the collapse of the 110-storey building.

Doany, who lives in Banyon, New Jersey, has worked as an auditor with Marsh and Mclennan Companies for the past year.

“Ramzi's office was on the 100th floor of the WTC north tower,” said his eldest brother, Ibrahim Doany.

“According to Marsh and Mclennan, ten people logged in to their computers that morning and Ramzi was one of them,” he told The Jordan Times.

“We have contacted the Jordanian embassy in Washington DC and they contacted Marsh and Mclennan, who told them the same thing they told us,” he added.

“The search is still on and so far no developments”.

His mother, Samia Doany, 60, a resident of Sterling, Virginia, arrived in Jordan two weeks ago to visit her other two sons. She explained that her calls to Ramzi's cell phone and apartment have gone unanswered since the tragic incident.

“He's not at all the type that won't call for so long, especially in such circumstances. He usually calls me every two days,” she told The Associated Press.

“It's very difficult to stay suspended like this. For me it's like being in torture...I feel very deeply with all those who lost loved ones,” she added.

With friends, family and neighbours calling the authorities and hospitals in New York, the search continues.

“We've even had neighbours try the house and our sister, Dina, who lives in Washington D.C. is on her way to New York to search for Ramzi,” said Ibrahim Doany.