Becker was appointed as sports attache to the African country in April, and lawyers for the 50-year-old German former tennis player lodged a claim asserting this should grant him immunity in the High Court on Thursday.
His position as ambassador to the European Union on sporting, cultural and humanitarian affairs is covered by the 1961 Vienna Convention on Diplomatic Relations.
This means Becker cannot be subjected to any legal proceedings without the consent of Foreign Secretary Boris Johnson and his counterpart in Bangui, his lawyers Sylvester Amiel Lewin and Horne said.
Becker was declared bankrupt in June 2017 by Registrar Christine Derrett. The tennis champion is currently selling memorabilia of his career including Wimbledon trophies to help pay off his debts.
The bankruptcy application was made by private bankers Arbuthnot Latham and Co in connection with a judgment debt owed to them by Becker dating as far back as 2015.
Becker said: “The decision to commence bankruptcy proceedings against me was both unjustified and unjust.
“A bunch of anonymous and unaccountable bankers and bureaucrats pushed me into a completely unnecessary declaration of bankruptcy, which has inflicted a whole heap of damage on me, both commercially and professionally, and on those close to me.
“I have now asserted diplomatic immunity as I am in fact bound to do, in order to bring this farce to an end, so that I can start to rebuild my life.”