It’s been hinted at for more than a year that a high-ranking Pakistani intelligence official was suspected of involvement in the November 2008 Mumbai terrorist attacks.

On Monday, a trial is slated to open in Chicago that could implicate the man identified as Major Iqbal of Pakistan’s powerful Inter-Services Intelligence Directorate (ISI) in a plot that killed 166 people during a three-day rampage by militants against a hotel and other civilian targets.

The trial opens amid the uproar over the ISI’s failure to identify the presence of terrorist leader Osama bin Laden, who lived for years near a Pakistani military school in the city of Abbottabad, not far from Islamabad. The founder of the terrorist network al-Qaeda was killed by U.S. commandos in a helicopter raid on May 2.

In April, Iqbal and three chiefs of Pakistan-based terrorist group Lashkar-e-Taiba were indicted in Chicago by US federal prosecutors on suspicion of involvement in planning the Mumbai attacks. The U.S. Justice Department has kept the indictment from gaining public notoriety by not issuing the usual press briefings for such a high-profile case.

The Chicago Tribune and Pro Publica, a private investigative journalism group, reported on the court filings that were finally made public earlier this month.

The trial in Chicago involves charges against Tahawwur Rana, owner of a Chicago immigration consulting firm who has been charged with material support of terrorism in the Mumbai case.

The main witness against him is David Coleman Headley, a Pakistani-American businessman-turned-militant who has pleaded guilty to helping to plan the attacks. In exchange for Headley’s cooperation, prosecutors have dropped their request for the death penalty against him.

Headley has told prosecutors that he convinced Rana to help arrange his scouting visits to Mumbai before the terrorist attacks by saying he had been “asked to perform espionage work for ISI,” Pro Publica quoted Headley as saying in a court document.

“I told (Rana) about my assignment to conduct surveillance in Mumbai? I told him that Major Iqbal would be providing money to pay for the expenses,” Headley is quoted as saying.

Monday’s trial opening will involve jury selection. Rana’s attorney contends that Rana is not a terrorist because he thought he was helping the ISI in a spying operation.

Nine of the 10 attackers died in the terrorist attack in Mumbai. In February, the lone surviving gunman was sentenced to death by the High Court in Mumbai.

In October 2010, the global police network Interpol issued international warrants for the arrest of five Pakistani nationals, including two Pakistani Army majors, one of them identified as Major Iqbal. The notices were issued after a joint probe by India’s National Investigation Agency and the US Federal Bureau of Investigation into Headley’s role.

New Delhi has accused Pakistan’s ISI of coordinating the Mumbai assault. Indian security officials have accused the Pakistani Army of having trained the Mumbai attackers, which Islamabad denies. Seven suspects are also on trial in a Pakistani court.

In March 2010, Headley pleaded guilty to 12 federal terrorism charges that also involved a plot against the offices of a Danish newspaper.