The UK has decided to cancel the refugee status of a former Kazakhstan banker accused of fraud after lobbying from the Asian state.
Mukhtar Ablyazov, previously Chairman of Kazakhstan's BTA Bank, was given an asylum status by the UK Home Office in 2011.
He left a year later after being sentenced by a High Court judge to 22 months in prison for contempt of court and has since been arrested in France.
His lawyers have accused the UK of violating international laws protecting refugees by engaging in communications over his asylum status with his country of origin and by refusing to release information to him about the contacts.
They claim they have secured documents which suggest UK Prime Minister David Cameron saw the issue as an obstacle to improving relations with Kazakhstan.
"After properly granting refugee status to Mr Ablyazov in 2011, the United Kingdom now seems to have fallen victim to an insidious misinformation campaign. The decision taken is not only unlawful and ungrounded, but the Home Office is not revealing the truth about it," Peter Sahlas, lawyer for the Ablyazov family, told the Financial Times in a statement.
London-based law firms, Reed Smith and Ronald Fletcher Baker, are acting on behalf of the Kazakhstan government in lobbying the UK government, according to documents obtained by Sahlas and seen by the UK newspaper.
In January the UK announced its intention to revoke the refugee status.
A recent memo from Reed Smith said the UK decision to revoke Ablyazov's refugee status was "being driven by the home secretary, Theresa May, as part of a wider 'clean-up' of asylum decisions that have been taken in recent years in respect of individuals who have abused the system and rules".
In a statement from his prison cell in Aix-en-Provence, Ablyazov told the Financial Times: "I have the deepest respect, Mr Cameron and Ms May, for what your country and your institutions stand for. Please recognise that you and your political institutions and courts are being manipulated by a kleptocratic dictator."
France agreed in January to extradite Ablyazov on fraud-related charges on request from Russia and Ukraine.
This month Ablyazov was granted an appeal against extradition and France's Cassation Court found ordered the case to be heard again, assigning it to a court in Lyon. However, the process could take months.