There has been no official comment on Mr Adams' detention. His paper said he was arrested in Bori, the main town in Ogoniland, while reporting in the area, where there have been protests against pollution by oil firms and demands by local people for a greater share in oil revenues.
Nine Ogoni minority rights activists, including the author Ken Saro- Wiwa, were hanged last November, triggering widespread condemnation of Nigeria's military rulers and sanctions against the country.
Mr Adams is now held in Port Harcourt, capital of the southeastern Rivers state, which includes Ogoniland, the Financial Times said. An official of the British High Commission had met him there for 30 minutes, the newspaper said.
Diplomatic efforts were continuing to secure his release and further meetings would be held today between British and Nigerian officials, it said.