BANGKOK
Thu May 21, 2015 3:09am EDT
Years of political violence in the Thai capital has strained police resources, delaying investigations into human trafficking in the south of the country and allowing the illicit trade to flourish, a top police official said on Thursday.

Southeast Asia is battling a migrant crisis that has seen hundreds of "boat people", mostly Rohingya Muslims from Myanmar and Bangladeshi migrants, pushed back out to sea by Thailand, Malaysia and Indonesia.

Migrants have long made their way from the Bay of Bengal to Thailand, but a crackdown on traffickers this year by the Thai government has disrupted the route, leaving many migrants aboard rickety boats with nowhere to go.

Thailand's deputy national police chief, General Aek Angsananont, said human smuggling and trafficking gangs were allowed to flourish in 2013/14 because police were unable to set up road blocks and other preventative measures as many officers were transferred to Bangkok during months of street protests that eventually led to a May coup.

"Look at Thailand last year. There was the coup and before that we had years of political problems," Aek told Reuters during an interview at parliament in Bangkok.

"Where do you think the police came from? They came from the provinces to back up Bangkok. We didn't have the resources to tackle the human trafficking problem.

"When were we weakest? Last year."

Speaking ahead of a regional conference to tackle Southeast Asia's migrant crisis, Aek said five investigations were currently underway into human trafficking but they could take months.

Thai police have arrested 43 people suspected of involvement in human trafficking including four police officers and some local politicians.

Aek said he has not found evidence of military complicity.

"I still haven't found evidence that it goes to the military. But let us be clear on one thing, no matter how important the person, we will catch them."

Police have not yet found evidence linking those arrested to more than 30 bodies uncovered at suspected trafficking camps near the Malaysian border last month, he said.

Last year, Thailand and Malaysia were downgraded to the U.S. State Department's lowest category - or Tier 3 - in its annual Trafficking in Persons Report, which assesses how governments around the world have performed in fighting human trafficking.