Adnan Abdulsamad and Ahmad Lari, who went to the public prosecution voluntarily, were accused of joining the previously unknown Hezbollah Kuwait, Abdulkarim bin Haider told AFP.
They were also accused of spreading false news that undermine Kuwait’s foreign position, he said. The two denied the charges.
The public prosecution was due to make a decision later Tuesday on whether to remand them in police custody or free them, probably on bail.
Two weeks ago, the prosecution interrogated eight leading Shiite activists over the same accusations. It freed them on bail after detaining them for several days.
The action came after activists from Kuwait’s minority Shiite community last month organised a rally to mourn Lebanon’s Hezbollah commander Imad Mughnieh who was killed in a car bombing in Damascus.
Mughnieh is suspected of hijacking a Kuwaiti passenger plane in 1988 in which two Kuwaitis were killed.
Abdulsamad spoke at the rally and described Mughnieh as a "martyr hero."
The prosecution had asked parliament to strip the two former MPs of their immunity to question them but parliament was dissolved by Kuwait’s ruler last week and their immunity was automatically lifted.
The crackdown on Shiite activists triggered angry protests with the case fuelling sectarian tensions in this oil-rich emirate where Shiites form about a third of the native population of one million.
Kuwait’s Emir Sheikh Sabah al-Ahmad al-Sabah on April 19 dissolved the opposition-dominated parliament calling for a new election on May 17, the second election in less than two years.
