The mother of Nigerian Finance Minister and former World Bank managing director Ngozi Okonjo-Iweala has been kidnapped from her home in the country's south, a statement from her ministry said.
"Earlier today, Professor (Mrs) Kamene Okonjo ... mother of the Coordinating Minister for the Economy and Minister of Finance, Dr Ngozi Okonjo-Iweala, was abducted from her home in Ogwashi-Uku, Delta State," the statement said on Sunday.
Finance Ministry spokesman Paul Nwabuikwu said the minister had received threats in the past.
"At this point, it is difficult to say whether those behind this action are the same people who have made threats against the coordinating minister in the recent past or other elements with hostile motives. No possibility can be ruled out at this point." Nwabuikwu said.
A security source said it was not clear whether the motive was political or ransom-seeking.
The source in Abuja said three people had already been arrested in connection with the kidnapping. He had no further details.
Kidnappings for ransom have occurred frequently in Nigeria's southern oil-producing Niger Delta region.
Local newspapers carry a story about a new kidnapping almost every day, often of professionals or relatives of politicians, but rarely anyone as high profile as the finance minister's mother.
Okonjo-Iweala has pushed to clean up corruption in one of the world's most graft-ridden nations, particularly related to a fuel subsidy programme alleged to be riddled with graft.
The minister has been struggling with fuel importers over payment of subsidies, with government officials delaying payments to allow for verification of claims.
The respected Okonjo-Iweala was earlier this year a candidate to head the World Bank, where she previously worked as a managing director. The job eventually went to Korean-American physician Jim Yong Kim though the Nigerian minister was viewed as a strong candidate to break the US lock on the post.
Nigeria is Africa's most populous nation and largest oil producer with some 160 million people.