The 47-year-old investment counsellor was nabbed by a team of Malaysia's Special Branch's Counter-Terrorism Division operatives at a condominium here yesterday.
Four other Maldivians, two men and two women, were also apprehended there.
Inspector-General of Police Khalid Abu Bakar said the man was suspected to be involved with the assassination plot, involving a bomb which was set off on board a speedboat carrying Yameen near Male on September 28.
"The suspect is a 47-year-old Maldivian man, who is also the country's investment counsellor," the police chief said.
In the attack, Yameen was unhurt, while his wife and two aides sustained minor injuries from the blast.