Bulgarian citizen Kiril Elevterov was kidnapped in Nigeria on the night of July 8 2007.
Elevterov was kidnapped together with a UK citizen and two Nigerians, Focus news agency reported.
The Bulgarian embassy in Nigeria and the Foreign Ministry confirmed the information.
Armed men in speedboats attacked a barge belonging to Nigerias Manipolu oil company and kidnapped the workers.
The Bulgarian and the Briton are employed by the UK EXPROGROUP oil company in southern Nigeria.
Bulgarias Foreign Ministry was taking all possible steps to secure the release of the Bulgarian, Focus said.
The incident occurred a day after three other foreigners were abducted from the area, industry and diplomatic sources said, according to Forbes.com.
No group has claimed responsibility for the kidnappings. This is the latest incident in a string of kidnappings of foreigners in southern Nigeria.
Another Bulgarian, working in Nigeria, was kidnapped in January 2006, but was released after 19 days.
