Boris Becker’s diplomatic passport is a “clumsy fake”, a Central African Republic foreign minister has claimed, in the latest instalment of the former tennis star’s bankruptcy saga.

The three-times Wimbledon champion is asserting diplomatic immunity under the Vienna Convention in his bankruptcy proceedings, and provided a High Court judge with a letter from the CAR embassy in Brussels stating that he is an attache for sports, humanitarian and cultural affairs in the European Union.

The letter stated that Becker was issued with a diplomatic passport on March 19 and that it runs until 2023.

However, a diplomatic passport requires the signature of the country’s foreign minister, Charles Armel Doubane. He claimed to Reuters that the version he has seen is a "clumsy fake", adding that "the signature on the passport was not mine".

Mr Doubane said the government is launching an inquiry into who issued the passport to Becker.