The mastermind behind the abduction of American vlogger Elliot Eastman has been arrested, Philippine police said today.

Alleged kidnapping ringleader Jackaria Jamani, 35, was detained by police on a ferry plying the Basilan Strait near Zamboanga del Norte province on January 7 evening.

Lieutenant Colonel Ramoncelia Sawan, acting information officer of the Police Regional Office 9, said: 'The suspect was arrested with the help of the police 55th Special Forces Company. He was caught in the sea between Basilan Strait and the boundary of Zamboanga City.'

Jackaria, also tagged as a supporter of the violent Islamist extremist group Abu Sayyaf, was detained at the Sibuco Municipal Police Station. He faces charges of kidnapping and serious illegal detention - both non-bailable offenses.

Authorities said they were investigating if he was linked to other abductions in the region.

American vlogger Elliot Eastman, 26, reportedly died on the night of his abduction from the poverty-stricken town of Sibuco in Zamboanga del Norte on October 17. The YouTuber was reportedly in the house with his Muslim Filipina wife Karisha Jala when four armed men allegedly burst through the door around 10pm.

He was allegedly shot while trying to resist the suspects but died while being whisked away on a boat.

Police arrived at around 11pm and took pictures of the suspected crime scene. Blood believed to be from Elliot's gunshot wound was smeared across a length of vinyl flooring. An empty bullet cartridge from an M16 rifle could also be seen alongside everyday items including a hat, handbag and food.

Hopeful authorities had for weeks been on a frantic search for the expat who they previously believed was still alive. The operation resulted in clashes with armed kidnapping groups on the conflict-torn island of Mindanao.

They announced he was believed dead on December 5.

Police said they have not yet found Eastman's body. Officials have also not clarified the motive behind the abduction.

Former Sibuco Mayor Norbideiri Edding said kidnappers may have targetted the American because they thought he was a rich foreigner and resentment that he was living with a local Muslim woman.