The United Kingdom has said it plans to build a prison in Nigeria to enable the government to transfer prisoners from Britain.
The proposed 112-bed wing, which will be built to United Nations specification in the Kiri Kiri prison in Lagos, will be built as part of a compulsory prisoner transfer agreement.
It will cost just under £700,000, according to a statement submitted to Parliament by Foreign Secretary Boris Johnson on Wednesday evening.
"As part of this agreement, eligible prisoners serving criminal sentences in Nigeria and the UK can be returned to complete their sentences in their respective countries," Johnson said.
It follows a deal reached between the two countries signed in 2014.
But poor conditions in some prisons overseas have created a legal barrier to returning foreigners convicted in the UK.
"The Government believes that wherever possible foreign nationals should serve their sentences in their own country," a Foreign Office spokesperson told Sky News.
"Helping Nigeria to improve its prison conditions and increase prison capacity will enable us to transfer more prisoners to Nigeria, which will in turn free up prison places in the UK."
Deals to transfer prisoners in UK jails to their countries of origin have been made with Albania, Rwanda, Jamaica and Libya, and well as Nigeria.
Johnson said tenders for the planned Nigerian jail had been placed and suppliers identified, bringing the project's total cost to £695,525 including support, monitoring and evaluation.
The bill will be met by the CSSF (Conflict, Stability and Security Fund), he said.