The man was reportedly snatched on Tuesday night along with an Italian, who has since been released. Neither have been named.

The British worker is reportedly being held hostage by youths demanding money.

Hostage taking is not unusual in the volatile Delta region where gangs of youths demand a greater share of the area's wealth for their impoverished communities.

Civil unrest

A Foreign Office spokesman said: "We are aware of an incident involving a British national and we are in touch with the company involved."

The Foreign Office's travel advice for Nigeria has been updated after an increase in civil unrest in the Delta region.

It advises: "Violent street crime and armed robberies are prevalent throughout the country. Travel outside cities after dark is unsafe and civil unrest has increased in the Delta region.

"There has been a recent increase in the number of incidents where expatriate workers, mainly in the oil and gas sector, are held hostage by their colleagues during industrial disputes or by local protesters at other times. These have so far been settled peacefully."