A US judge has refused to let federal prosecutors present some of the most potentially damaging evidence against a Yemeni tribal leader charged with funneling millions of dollars to outlawed groups. Judge Sterling Johnson ruled on Tuesday that prosecutors will not be able to present documents allegedly linking Shaikh Muhammad Ali al-Muayyad to suspected al-Qaida members in Afghanistan and Croatia. The case of al-Muayyad and his Yemeni assistant Muhammad Zayid - who are charged in federal court in Brooklyn with supporting al-Qaida and the Palestinian resistance group Hamas - is to begin on Thursday. If convicted, the 56-year-old al-Muayyad could face more than 60 years in prison. Zayid, 31, could also face more than 30 years. The government had hoped to prove al-Muayyad's ties to al-Qaida leader Usama bin Ladin with address books containing his name and phone number, which were confiscated from suspected al-Qaida fighters being expelled from the former Yugoslavia. The government also planned to introduce an admission form for an al-Qaida Afghan training camp that used al-Muayyad as a reference. But the judge called the Croatian evidence "so remote, I am going to preclude the government from using it". He went on to exclude the Afghan evidence, apparently agreeing with a defence argument that the presence of al-Muayyad's name on the form was not sufficient proof of wrongdoing. "We don't know who put this name in," the judge said.