Nasir Najr al-Mutairi has remained in police custody since his return home on 15 January after three years in Guantanamo, Cuba, despite appeals to free him on health grounds.
He was charged with working for a foreign country which undermined Kuwait's political position; committing an act of aggression against a foreign country, thus endangering Kuwait's relations; and training in the use of arms, lawyer Mubarak al-Shimmari said on Wednesday.
The criminal court, which held its first hearing on al-Mutairi's case, adjourned until 13 April and turned down a request by the lawyer to free him on bail.
"My client was in the courtroom and denied all the charges. I submitted documents proving the court is not competent to hear such cases based on verdicts in similar cases," al-Shimmari said.
"My client was in the courtroom and denied all the charges. I submitted documents proving the court is not competent to hear such cases"
Mubarak al-Shimmari, lawyer for Nasser Najr al-Mutairi
He added that al-Mutairi, 26, was not involved in fighting when he was in Afghanistan, but had been there with a Kuwaiti relief committee.
Al-Mutairi was released following an agreement between the United States and the Kuwaiti government. Eleven Kuwaitis are still detained in the US naval base in Guantanamo Bay.
According to the US lawyer defending the Kuwaitis, Tom Willner, most of the Kuwaiti detainees "were captured by bounty hunters in 2001 near the Afghan-Pakistan border and sold to the United States".
About 550 people, most of them captured during the US-led war in Afghanistan in late 2001, are being held as "enemy combatants" at a tightly controlled prison at the US base in Cuba.