A Somali aid worker seized by gunmen along with two Westerners in northern Somalia was being questioned by police about the kidnappings, the Danish Refugee Council (DRC) said on Wednesday.
An American and a Dane also were kidnapped on Tuesday while on assignment with the Danish Demining Group which clears landmines in the Horn of Africa country, the second capture of Western aid agency staff in the region this month.
The Somali aid worker, (who was) also missing, is now in the custody of the local police, and his role in the incident will be further investigated, the DRC said in a statement.
It was not immediately clear how the local aid worker wound up in police custody.
The Danish Demining Group, which is part of DRC, works in 10 countries, including Afghanistan and Iraq, clearing landmines and unexploded ordnance.
The two international staff members, who were kidnapped in Galkayo in the northern Somalia, are still not released. One is a Danish man and an American woman, it said.
Galkayo straddles the border between the semi-autonomous Somali province of Puntland and the Galmudug region. Al Qaeda-linked al Shabaab rebels do not have a strong presence there.
Somali gunmen kidnapped two Spanish staff working for Medecins Sans Frontieres (MSF) from the Dadaab refugee camp in northern Kenya on October 13 and took them across the border into the anarchic Horn of Africa nation.
A Somali pirate who gave his name as Abdi told Reuters from Galkayo that a group of pirates was behind the abduction and the captives were being taken to a coastal haven.
Somali pirates have made millions of dollars from hijacking ships in the busy shipping lanes off Somalia and keeping the crews hostage until ransoms are paid for their release.
Besides the abduction of the Spanish aid workers, suspected Somali gunmen also seized a British tourist from a northern Kenyan beach resort in September and a French woman from the same area on October 1. The French woman later died.
(Writing by Aaron Maasho in Nairobi; Editing by David Clarke and Michael Roddy)