Police are interviewing the three victims from the second camp.
The advocacy organization Human Rights Watch has said that human trafficking is out of control in Thailand. It said the dead at the first camp, which was found Friday, were Rohingya Muslims from Myanmar
CNN's Freedom Project
works in Thailand as part of its effort to eliminate human trafficking.
Human Rights Watch said the first camp was discovered in the Sadao district of Songkhla province, in southern Thailand, near the border with Malaysia.
Fourteen high-ranking police officers were transferred out of the area while investigations are conducted into whether they helped cover up the existence of the camps, police Gen. Aek Angsananont told CNN.
"There are solid grounds showing that these police have been negligent in their duties," Aek said. "How could they allow these detention camps to exist on their turf? We are investigating further whether these people played any role regarding these camps."
Police are searching for any more secret camps that may exist, he said.
Police, NGO say deaths were from disease, not violence
In a statement last week, Human Rights Watch said the dead found at the first camp had "starved to death or died of disease while being held by traffickers who were awaiting payment of ransoms."
Police told CNN that five people were in custody -- both Thai and Rohingya -- in connection with the first camp discovered last week.
They said some of the Thais were local governmental officials. They were acting as camp managers and middlemen, he said. They said a court had issued eight arrest warrants, but three of the accused were still on the run.
Aek said the remains found at the first camp are believed to be from people who died between three months and one year ago. Of the 26 bodies, 24 were those of men, one was that of a woman, and one has yet to be identified.
He told CNN that the initial forensic examination showed no signs of violence and that police believe the people died of illnesses.
Thailand has worst possible ranking for trafficking
Last year, the U.S. State Department downgraded Thailand to the worst possible ranking -- Tier 3 -- in its Trafficking in Persons report. It said Thailand is a source, a transit point and a destination for trafficking.
The report also said that ethnic minorities and citizens of neighboring countries were especially at risk of exploitation in Thailand through forced labor or the sex trade.
Report: Rohingya among the most vulnerable
The fate of Rohingya Muslims was an area of particular concern for the State Department. The 2014 trafficking report said the Rohingya are among those most vulnerable.
They are a stateless people who have been fleeing ethnic violence in Buddhist-majority Myanmar for years. The Rohingya usually arrive in southwestern Thailand by boat and travel from there to Malaysia, where they often work illegally.
In January 2014, Thai police found hundreds of Rohingya men, women and children in a camp in the same province and near the same town where the bodies were discovered Friday.