The suspect's DNA did not match the sample found on evidence believed to have been left behind in an escape taxi by the bomber, police said.
The Turkish embassy said in a statement Thursday that it had received no alerts from Thai officials about the suspects' nationalities.
After initial conversations with the survivors, officials believe that the boat's passengers were undocumented migrants.
The 38-year-old man had allegedly contacted Wanna Suansan, the only female suspect in the blast investigation.
Thai police believe that the main suspect is a member of China's Uighur ethnic minority based on travel documents, but have yet to authenticate his passport.
An explosion at a Hindu shrine in the Thai capital on Aug. 17 killed 20 people and injured over 120. Thai police have also issued arrest warrants for three more foreign nationals.
Phuketwan's editor and reporter were facing up to seven years in prison for a report on the Thai navy's alleged involvement in trafficking of refugees.
All of the 244 foreign nationals taken into custody during the sweep had prior criminal convictions, with 56 percent having felony convictions.
Earlier on Monday, police announced they had found bomb-making materials in an apartment near where the main suspect of the Aug. 17 bombing was arrested.
Police probing Thailand's deadliest bombing widened their net in the search for more suspects on Sunday after a foreigner was arrested and stacks of fake passports and bomb-making materials were found.
Authorities arrested the man in Nong Jok on the outskirts of Bangkok Saturday and also found bomb materials in his apartment.
The Erawan shrine bombing that killed 20 isn't expected to overly affect tourism, either, a Thai official said Friday.
Just a day after the Erawan Shrine attack that left 20 people dead, an explosion took place at the Sathon ferry pier, causing no casualties.
Prosecutors said that Scott Stammers was involved in scheme to transport nearly-pure methamphetamine from North Korea on two different occasions, in 2012 and 2013.
Police and security analysts have raised the possibility of the involvement of Uighurs in the Erawan Shrine bombing.
The ivory, seized during a series of raids earlier this year, was destroyed in a public ceremony attended by Prime Minister Prayuth Chan-ocha.
The Cambodian government has been cracking down on marijuana for the past 15 years.
Emerging markets in Southeast Asia will suffer the most from Chinese devaluation but are protected from some of the worst losses seen in 1997.
Police are putting "pieces of the puzzle together" to find the bomber who killed 20 people at the Erawan Shrine.
A man in a yellow shirt was caught on CCTV leaving the scene on the back of a motorcycle taxi.
Authorities have discovered skeletons they believe to be of human-trafficking victims close to where the remains of more than 130 people were found in May.
The blast last Monday at one of the capital's most famous shrines, packed with Asian visitors, will inevitably dent the tourist industry, one of the economy's few bright spots.