A Canadian man who went missing eight days ago in Colombia is believed to have been kidnapped, a Colombian army official said Friday.

Thomas Orland MacLean, 46, believed to be an electrical engineer from Ottawa, was last seen on the evening of June 26 along with his brother-in-law, a cattle rancher from Pereira, Colombia, named Jesus Salvador Aristizabal Zuluaga, said General Justo Eliseo Pena, commanding officer of the third division of the Colombian army.

The two men had been driving off a ranch that had been rented by Aristizabal Zuluaga near Tulua, which is about 150 kilometres west of Bogota, Pena said.

Witnesses later saw Aristizabal Zuluaga's pickup truck being driven from the scene by two hooded men dressed in civilian clothes. It was later found abandoned with Aristizabal Zuluaga's 9-mm pistol still in it.

The municipality has offered a reward for information about the disappearance of the two men, said the town's secretary general, James Arturo Visnaco.

He said the mountains around Tulua and the Valle del Cauca region are known to be home to guerrillas from the Revolutionary Armed Forces of Colombia — or FARC, from its Spanish initials — an insurrectionist group that funds many of its activities by demanding ransoms for high-profile captives.

He added that local people are generally aware of that, but these two were not from the local area and may not have had the same information.

So far, however, no group has claimed to have the two men and no ransom has been demanded, and both the army and the municipality are cautioning against jumping to the conclusion that FARC is involved, particularly because FARC members normally wear military uniforms.

There are also a number of paramilitary and criminal groups in the area.

FARC was established in the 1960s as the military wing of the Colombian Communist Party. The militant group later became involved in the cocaine trade as a means of raising funds.

The Colombian government estimates the group has between 6,000 and 8,000 armed members and a military presence in 15 to 20 per cent of the country, particularly remote jungle and mountain areas.

Some estimates put the number of FARC fighters at as many as 18,000. The governments of Canada, the United States and the European Union all consider the organization a terrorist group.

On Wednesday, 15 hostages, including former Colombian presidential candidate Ingrid Betancourt, were rescued from FARC by Colombian military agents who posed as members of the militant group.