After three days on the runin the northern province of Lampang, Pol Sgt Manas Suapho of the Bangkok Metropolitan Traffic Police contacted a high-ranking police official and offered to turn himself in.
Police took him to the Royal Thai Police Headquarters in Bangkok for further questioning by Metropolitan Police chief Kamronwit Thoopkrachang.
Pol Sgt Manas said at a press conference on Wednesday that he had transported drugs about 10 times since 2010 and earned between one million and 2.2 million baht for each delivery.
"My friend, who is a former police officer at Pracha Chuen police station, asked me to join the drug trafficking ring.
"I received the drugs at the border in Chiang Rai province and my job was to deliver them to Bangkok," said the Bangkok police sergeant major.
He said an agent he knew only as "Jae Pen" would contact him once the drugs were in the capital.
"I stopped delivering drugs three to four months ago now because I was afraid of being caught, but Jae Pen asked me to do it one last time. I agreed and got arrested in the end," he said.
He said he used his Mercedes or BMW to transport the drugs, but had never used his police badge to facilitate his crime.
"I was not thinking when I ran away, but I'm not afraid of death. I believed police would not shoot at a fellow officer and I didn't know where to hide.
"I've told my wife and family about this and I believe I'll receive fair treatment," Pol Sgt Manas said.
On Sunday night, the 42-year-old fugitive fled into a forest in Lampang's Ngao district, abandoning his vehicle that was found to contain 2.48 million methamphetamine pills, or yaba, and five kilogrammes of crystal methamphetamine, or ya ice.
Another suspect, in another car, was arrested at the same road block.
Police have seized some of Pol Sgt Manas' assets, and obtained arrest warrants for six other suspects, including a former policeman.
Meanwhile in Chiang Mai, police arrested a six-member Hmong hilltribe drug gang and seized speed pills with an estimated street value of 120 million baht.
Kriangkrai sae Lawua, 23, and five other suspects – all Hmong men -- were brought before a press conference in Bangkok on Wednesday, by Deputy Prime Minister Chalerm Yubamrung and national police chief Adul Saengsingkaew.
They were arrested in Chiang Mai's Doi Saket district on Saturday.
Police also confiscated from them valuables such as cars and mobile phones.
Pol Gen Adul said anti-narcotics police had learned that the gang planned to traffic drugs from the Thai-Myanmar border and deliver them to a customer in Chiang Mai. They set up a surveillance operation on routes police believed the suspects might use.
Police located the gang's vehicle near Doi Mae Salong, a main attraction in Chiang Rai's Mae Chan district, and followed it until it stopped at a house in Doi Saket where the officers showed themselves.
Police found 400,000 yaba pills hidden in the back of the suspects' pickup truck, which had been modified, with a secret compartment.