He was taken on Tuesday by officers of the Judge Advocate General's Department to the Crime Suppression Division (CSD) headquarters along with his four alleged accomplices - Nongnuch Sithirat, Panthong Siriwan, Chanthima Chotkittikasem and Surat Phumphuang.
They were subsequently charged with extortion, illegally acting as middlemen demanding or acceping bribes and money laundering.
The officers from the Judge Advocate General's Department had earlier filed a complaint against Maj Gen Jennarong and his co-accused, with evidence against them including photo copies of 27,000 baht in cash allegedly paid to them by vendors, four mobile phones, a list of vending stalls that paid them protection money, a financial account, and hard disks from closed-circuit television cameras at Tawanna Hotel on Surawong road in Bang Rak district.
A group of Patpong vendors turned up at the CSD headquarters and gave flowers to Maj Gen Jennarong in a show of support.
From the CSD, the military and police were to take the five suspects to the Bangkok South Criminal Court and seek permission to detain them for further investigation.
Maj Gen Jennarong, 55, is accused of colluding with four civilians to demand bribes from street vendors at Patpong on tourist-crowded Silom road.
The alleged extortion racket also reportedly involved officers from a nearby police station.
The five were later released on bail.