Eighty percent of violent incidents in the far South were "side issues" not perpetrated by insurgents but are believed to be linked to insurgent groups, according to the Internal Security Operations Command.
Col Jatuporn Klampasut, director of the side issue intelligence unit at the Isoc's Region Four forward command, said the issues make up 80% of the violence while the rest were created by insurgents driven by ideology.
The "side issues", a term coined by Prime Minister Prayut Chan-o-cha when he was army chief, include security incidents related to contraband oil networks, smuggling of untaxed goods, illicit drug and human trafficking rings, gambling dens, illegal logging and activities carried out by influential figures.
He said many suspects have been arrested in the incidents and solid evidence has been seized from them since 2011.
Col Jatuporn said the contraband oil businesses alone generates more than 200 million baht a month. Untaxed goods account for about 300 million baht and illicit drug trafficking about 200 million baht a month.
The chief of intelligence said traffickers have assisted about 20,000 Rohingya boat people to find temporary refuge at 24 places in Songkhla's Sadao district before the Rohingya continued to their destinations.
Rohingya traffickers were also linked to networks which brought in Uighurs, who fled China, and secured fake passports for them. The authorities believe the human traffickers active in the far South are also connected to suspects in the Erawan Shrine bombing attack last year.
Col Jatuporn said illegal loggers were based in the Tawe Mountain Range in Rangae district of Narathiwat.
Loggers cut down the protected takien thong wood and the logging areas double as training areas for insurgents.
Since 2008, authorities discovered 48 logging sites which also operate as insurgent training camps, 28 of them in the Tawe mountains.
The loggers supplied food to the insurgents, Col Jatuporn said.
He added that part of the money made from the illegal side issue activities is believed to have been donated at religious ceremonies.
Rear Adm Somkiat Polprayoon, deputy director of Isoc Region Five, said there have been more than 15,000 violent incidents in the far South in the past 12 years since the security flare-up, during which time 7,100 people have been killed.