The treason trial of suspected Nigerian militant Henry Okah resumes Monday at a closed federal high court in the central city of Jos.  From the Nigerian capital Abuja, Gilbert da Costa reports Okah could face additional charges.

Henry Okah, a suspected leader of the Movement for the Emancipation of the Niger Delta, MEND, is facing 55 counts of treason, terrorism, illegal possession of firearms and arms trafficking.

Okah's defense lawyers are barred from making details of the hearing public, but a member of Okah's defense team, who asked not to be named, told VOA prosecutors plan to bring seven additional charges against his client at Monday's closed court session.

"They've increased the charges from 55 to 62," said the lawyer. "They want to pre-empt our appeal but it won't be acceptable to us. Already, we are on appeal and one of the things we are appealing against is the fact that out of the 55 charges, the judges only read out two to him. By criminal procedure law, they are supposed to read all of them, even if he keeps mute or not. This is the fourth time they are amending the charges since we started."

Court proceedings against Okah began in April. President Umaru Yar'Adua has argued that the proceedings must be kept secret for the sake of national security.

Lawyers for Okah say a closed trial is an infringement of his rights and have asked a superior court to overturn the decision.

Okah was arrested on suspicion of arms smuggling in Angola in September last year and faces the death penalty.

The Movement for the Emancipation of the Niger Delta has claimed responsibility for a series of attacks on Nigeria's oil infrastructure that have cut daily production by about one quarter and pushed up international crude prices.

The group has vowed to increase attacks on oil installations to pressure the government to free Okah and give a greater share of oil profits to the impoverished delta region.