Hamburg, Germany ? Germany’s investigation into the Hamburg suicide hijackers after the Sept. 11 attacks kept returning to one man: Ramzi Binalshibh.

Binalshibh was apprehended this Sept. 11, in Karachi, Pakistan, after a raid by Pakistani and CIA operatives.

Pakistan police escort a blindfolded Ramzi Binalshibh after a gunbattle between police and suspected al-Qaida members in Karachi, Pakistan. Binalshibh, believed to be a key planner of the Sept. 11 terror attacks, is expected to be a font of knowledge about al-Qaida's Hamburg, Germany, cell..

With Binalshibh now in custody, German officials want to bring the 30-year-old Yemeni back on an international warrant for allegedly providing logistical support for the Hamburg cell.

Binalshibh first came to Germany on a scholarship to study at Hamburg’s Technical University, where at least five of the terrorists were students, meeting the cell leader Mohamad Atta early in his stay.

Atta and al-Shehhi, who were cousins, were the first two chosen as pilots in the attacks. Atta then chose Binalshibh and Zaid Jarrah to fly the other two planes, federal prosecutor Kay Nehm said last month.

At the end of November, 1999, the four prospective pilots Binalshibh included traveled to Afghanistan to secure financial and logistical help for the planned attack. They returned to Hamburg in the summer of 2000.

Despite repeated attempts, Binalshibh was denied a visa to the United States to attend flight school with Jarrah in Venice, Fla., while al-Shehhi and Atta studied at another school in the same city.

Zakariya Essabar, a Moroccan and part-time Marienstrasse resident, was chosen to take his place, but his visa was rejected.

They settled on Zacarias Moussaoui, who went to the United States in February 2001, but was arrested that August when instructors at his Minnesota flight school grew suspicious.

Moussaoui is in U.S. custody and on trial for his alleged role in the attacks.

But just because he was out as a pilot didn’t mean that Binalshibh was out of the plot.

“After his exclusion as the fourth pilot, Binalshibh became the most significant contact person inside the network,” Nehm said.

In an interview aired last week on the Arab al-Jazeera satellite television network, a man identified as Binalshibh acknowledged as much: “I was in charge of coordination between the cells and the central command in Afghanistan and setting the priorities of the cells’ operations until the mission was accomplished.”

In that role, he arranged payments to flight schools and made frequent organizational trips, prosecutors said. He met with Moussaoui in London in December 2000, and traveled to Yemen, London, Iran and Afghanistan in 2001. The Iran-Afghanistan trip was funded by money wired from Atta, Nehm said.

Binalshibh worked closely with Bahaji and Zakariya Essabar, who also are being sought on international arrest warrants by Germany.

All of them disappeared around the time of the Sept. 11 attacks with Binalshibh being last seen in Hamburg in August 2001.