Nigeria has outlawed gay marriage, public displays of same-sex relationships, and belonging to gay groups with the passing of a law that has sparked international condemnation.
President Goodluck Jonathan's spokesman, Reuben Abatim said on Monday that the president signed the bill because it was consistent with the attitudes of most people towards homosexuality in the west African nation.
"I can confirm that the president has signed the bill into law," Abati said, without specifying a date but adding that it happened earlier this month.
"More than 90 percent of Nigerians are opposed to same-sex marriage. So, the law is in line with our cultural and religious beliefs as a people," he added.
"And I think that this law is made for a people and what [the] government has done is consistent with the preference of its environment."
Amnesty International urged Jonathan to reject the bill, calling it "discriminatory" and warning of "catastrophic" consequences for Nigeria's lesbian, gay, bisexual and transgender community.
Under the terms of the law, anyone who enters into a same-sex marriage or civil union can be sentenced to 14 years in prison while any such partnerships entered into abroad are deemed "void".
It also warns that anyone who registers, operates or participates in gay clubs, societies and organisations or who directly or indirectly makes a public show of a same-sex relationship will break the law. Punishment is up to 10 years in prison, it adds.
"Only a marriage contract between a man and a woman shall be recognised as valid in Nigeria," the law states.
Nigeria is a highly religious society, with its 170 million people roughly divided in half between Christians and Muslims, though a significant number are also believed to follow regional religions.
The anti-gay law follows similar legislation in Uganda that was condemned by the US president, Barack Obama, as "odious". South Africa's Archbishop Desmond Tutu compared it to apartheid.