(CNN) -- A Nigerian militant group said it plans to release a British oil worker Monday as a birthday "gift" to Matthew John Maguire, who was abducted last year.
"Today, June 1 is Mathew (sic) Maguire's birthday," according to an e-mail sent Monday by Jomo Gbomo, a spokesman for the Movement for the Emancipation of the Niger Delta (MEND).
"He has spent close to 9 months in captivity and we hope to release him today as his gift."
Maguire was taken hostage along with 26 other oil workers when their oil boat was hijacked in September, according to British media reports.
All the others have been released, including Barry Hughes, a sick British oil worker who was freed in April.
MEND said it wanted to alert the British High Commission "of our intentions" to release Maguire so they can "put a leash" on Nigerian government forces "who may plan to ambush the fighters along with Mathew (sic) to score cheap publicity that he was rescued by them."
The British Foreign Office said it is aware of the reports and is "making inquiries at present."
"We call for the unconditional release of all hostages," said a spokeswoman, who declined to be named because of standard policy.
MEND had threatened that Hughes and Maguire would be held hostage until the Nigerian government releases one of the group's members, Henry Okah, who was taken into custody last year and who, according to local reports, is charged with treason.