A Japanese man abducted by suspected Al-Qaeda linked militants last month in the southern Philippines is alive, officials said Sunday.

Toshio Ito, also known Amer Katayama Mamaito and his captors were sighted recently on the main island of Jolo, siad Sakur Tan, governor of southern province of Sulu and head of the crisis group working for the release of foreigners.

Mamaito, 63, was forcibly taken by 10 armed men on July 16 in the village of Bangkilay in Pangutaran Island of Sulu. He has been living on the island since 2004 and is reportedly a treasure hunter.

"He is alive based on the reports we get from the field. We are working out for his freedom," Tan said.

The group holding the foreigner has not yet demanded ransom in exchange for their captive's freedom, Senior Superintendent Alex Lineses, regional police intelligence head, said.

In January last year, three international aid workers of the International Committee of the Red Cross (ICRC) were kidnapped after inspecting a water and sanitation project at a jail in Sulu.

Eugenio Vagni, the Italian worker of the ICRC, and colleagues Andreas Notter of Switzerland and Mary Jean Lacaba of the Philippines were released by their Abu Sayyaf captors separately.

The 380-strong Abu Sayyaf group, founded in the early 1990s by Islamic extremists, is notorious for kidnapping, bombing and even beheading in southern Philippines over the past decade. The group was blacklisted by the United States as a foreign terrorist organization.