Sri Lanka on Monday deported a Maldivian teenager wanted in an investigation into an explosion on a boat carrying Maldives President Abdulla Yameen, Reuters said, citing government and high commission officials.

The deportation comes after the U.S. Federal Bureau of Investigation said it had found no conclusive evidence that the Sept. 28 explosion was caused by a bomb.

Yameen, 56, was unhurt in the blast as his presidential boat approached the capital Male while he was returning from Saudi Arabia after the Haj pilgrimage, but his wife and two aides were injured.

Sri Lanka's immigration officials deported an 18-year old Maldivian national, but declined to give details, Reuters said.

"On the request from the Maldivian High Commission, an (immigration) investigation team arrested the Maldivian and sent him back in a flight today after cancelling his visa," Lakshan Zoysa, a spokesman for the immigration office, told Reuters.

An official at the commission said the person arrested was one of eight wanted in connection with the blast. Maldives police on Saturday arrested seven people.

"He is a social media guy and die-hard supporter of the arrested vice president," the official told Reuters.

Maldives Vice President Ahmed Adheeb was arrested last month in connection with the explosion and has denied wrongdoing. Defence Minister Moosa Ali Jaleel was sacked in mid-October.

The Maldives initially said the blast could have resulted from mechanical failure, but it later said the blast was an assassination attempt.

Yameen has provoked street protests in the Maldives with a crackdown on political dissent, including the arrest of the country's first democratically elected president, Mohamed Nasheed, who was sentenced to 13 years in jail this year on terrorism charges that have caused an international outcry.