Pirates have reportedly abducted five crew members from a general cargoship off Nigeria on Tuesday.
The 711-dwt Cap Saint Georges (built 1973) was attacked 28 nautical miles (52 km) south-east of Bonga.
The seized seafarers were reported as three Cameroonians, a Ghanaian national and one Sierra Leonean, according to security company Ambrey.
Ambrey said its source was of "moderate" reliability. Dryad Global later reported the kidnapping with a "high" degree of confidence.
The vessel had been underway at six or seven knots before it drifted for about 47 minutes.
The Cap Saint Georges was underway from Douala, Cameroon, at the time, heading north-west towards Lome in Togo.
Kidnapping total rises
Equasis reports the ship was sold to undisclosed interests before December, and lists it as laid up.
The last AIS update showed the vessel stopped in Lome on 12 December.
A previous kidnapping in the Gulf of Guinea occurred at the end of November, when four seafarers were taken from a tanker managed by Evangelos Marinakis-controlled Capital Ship Management.
The 38,000-dwt Agisilaos (built 2006) was attacked by an unknown number of gunmen while underway in Ghanaian waters, 75 nautical miles south of Lome in Togo.
That incident was the 24th confirmed kidnapping incident in the waters of the Gulf of Guinea this year, with 122 crew kidnapped from vessels.
Earlier on Monday, a reported boarding of a Greek tanker off Nigeria was labelled a false alarm.
