NAIROBI (Reuters) - A former World Bank economist whose detention in South Sudan has caused an international outcry was one of seven men charged on Monday with insurgency and sabotage, more than seven months after his arrest.

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Peter Biar Ajak, who is country director for his native South Sudan for the International Growth Centre which studies emerging economies at the London School of Economics, had been held since last July.

He had not appeared in court until last Thursday, despite months of calls by U.S. senators and other international figures for him to be charged or released.

Biar’s lawyer and lawyers for the other defendants denied the charges against them, which were brought on Monday under anti-terrorism and security laws.

Appearing in court on Monday, Biar repudiated a document that was presented as his statement.

“The investigation was conducted under gunpoint to my head,” he said.

His lawyer, Monyluak Kuol, asked for the case to be dismissed, telling the court Biar was a civilian with no connection to the charges against him.

Ajak Mayol Bior, lawyer for one of the other defendants, businessman Kerbino Wol, said no act of terrorism had been committed and charges of arms possession were fabricated.

A childhood refugee from the long war that ended with South Sudan’s independence from Sudan in 2011, Biar fled to the United States as a youth, was educated at Harvard and Cambridge and later worked at the World Bank. His supporters say he was promoting South Sudan’s peace process when he was arrested.

South Sudan has been in a state of civil war since 2013, two years after its founding, after political disagreements between President Salva Kiir and his then deputy, Riek Machar, degenerated into a military confrontation.

At its peak, the conflict uprooted a quarter of the country’s population of 12 million and devastated its oil-dependent economy. A regionally brokered deal last year, which had Machar return to government again as Kiir’s deputy, ended the fighting although pockets of violence remain in some parts.