Nigeria's former President Goodluck Jonathan has denied he rejected a British offer to rescue the Chibok girls abducted by Boko Haram.
The Royal Air Force (RAF) located the more than 200 girls and proposed to rescue them but Mr Jonathan refused, the UK's Observer newspaper says.
A spokesman for Mr Jonathan dismissed the paper's report as "lies".
The Chibok abduction sparked global outrage and led to one of the biggest social campaigns in recent years.
The Observer says the RAF conducted air reconnaissance over northern Nigeria for several months in 2014, as part of a mission named Operation Turus, following the kidnapping of the schoolgirls by the Islamist militant group.
The paper's report is based on claims made by an unnamed source which it says was involved with Operation Turus.
Mr Jonathan's spokesman, Ikechukwu Eze, said: "We can confidently say the lies in this report are self-evident."
He said that Mr Jonathan's administration had allowed neighbouring countries to help with the rescue attempt and let Western military conduct reconnaissance flight over the country's airspace.
Nigeria's Daily Trust newspaper quotes Mr Eze as saying that the reports were the result of people "playing politics with the issue of the Chibok girls".
The lack of progress against Boko Haram was among the issues that is considered to have cost Mr Jonathan his bid for re-election in 2015.