Andre Kasongo Ilunga was the rising star of Congolese politics. Just 34, he had risen from obscurity to be appointed minister for foreign trade in Congo's first democratic government last month. Then, before he had even started work, he resigned. Sadly, Mr Ilunga will never be able to articulate the reasons why. For he does not exist.

In a bizarre case that has captivated the Democratic Republic of Congo, Mr Ilunga appears to have been exposed as the creation of Honorius Kisimba Ngoy, leader of the Unafec party.

The affair of the "phantom minister" - as local media have called it - has led to calls for an investigation into Mr Kisimba and an inquiry into how the prime minister could give such a prominent post to someone he had never met.

"It's just bizarre," Charles Yoshad, a civil servant, told Reuters. "Nowhere else in the world would you attempt to swear in a ghost."

The saga began when the prime minister, Antoine Gizenga, asked parties in the ruling coalition to nominate two candidates for a ministerial post. Mr Kisimba nominated himself and Mr Ilunga, allegedly the party's vice-president. One political analyst said Mr Kisimba believed this would guarantee him a cabinet seat. But the stunt backfired when Mr Ilunga was given the post on February 5.

Mr Kisimba then handed a letter to the prime minister announcing that Mr Ilunga had quit. But Mr Gizenga said that until the letter was delivered in person, the post would remain Mr Ilunga's. Three men stepped forward claiming to be the mystery man, but all were exposed as frauds.

Mr Kisimba insists Mr Ilunga is a real person with "secret" reasons for resigning. "He wrote it himself," he said. "He signed it. Could an imaginary man do that?"