The lead investigator at Bangladesh's new war crimes tribunal, set up to prosecute perpetrators of atrocities during the 1971 independence war against Pakistan, resigned Wednesday, an official said.

Abdul Matin, a former top bureaucrat, submitted his resignation in the wake of allegations by senior officials that he had ties to the country's main Islamist party, Jamaat-e-Islami, which sided with Pakistan during the war.

"He resigned citing personal reasons," the home ministry's senior information officer Mohammad Sahenor Miah said.

Matin was named the head of the seven-member investigation team for a special tribunal, set up in March this year, to prosecute Bangladeshis who sided with Pakistan and committed murder, rape and arson during the war.

Leaders of Jamaat-e-Islami have been accused of both committing and facilitating the murder of freedom fighters and many of the country's intellectuals during the nine-month struggle.

Last month Alauddin Ahmed, an advisor to Prime Minister Sheikh Hasina, accused Matin of being a key activist for the Islamic Chhatra Sangha -- the now defunct student wing of Jamaat.

Matin has vigorously denied being a member of the student wing, saying that he was neither a freedom fighter nor an activist for any group which opposed the liberation struggle in 1971.