The last call between missing German sports-car tune-up wizard Uwe Gemballa and wife Christiane was in English, a language they never spoke to each other.
They spoke after Gemballa, world renowned for upgrading Porsches and Ferraris for rich clients, landed at OR Tambo International.
Saying he was involved in a "little accident", he asked her to transfer à1-million (R9.4-million) urgently to a bank account on February 9.
South African and German police, Interpol and private investigators have found no leads. Interpol is listing him as a missing person.
His wife spoke to the Sunday Times this week via e-mail, as well as a family friend in Cape Town, who asked for his identity to be protected as he feared for his safety.
"A lot of big names connected to the underworld have come up during our search for Uwe. I don't want to put my own family at risk," he said.
Strip club boss Lolly Jackson's murder two weeks ago put the spotlight back on Gemballa when it emerged Czech billionaire Radovan Krejcir was helping police probe Jackson's death.
Newspapers reported that Gemballa was due to meet Krejcir at OR Tambo airport to discuss setting up a South African franchise of his firm, Gemballa Automobiletechnic. However, the Czech denied meeting the German there.
The family thinks Gemballa's last call was a ransom demand. The friend said: "Christiane knew something was radically wrong when Uwe spoke . English. She believes he must have been forced to make that call."
Christiane said her husband called from a number not known to her. "He spoke to our son, and told him to give the phone to me immediately.
"I asked him why he was talking to me in English, but he did not answer. He repeated his sentence in English. He told me to call again regarding the account details. Since then we have heard nothing."
The family did not transfer the money. Christiane said things were "very bad" for her and their teenage son.
The friend said the police said they saw this as a missing-person case. "They say Uwe might have had an argument with his wife and chose to disappear."
The family is upset by German reports that Gemballa staged his disappearance to avoid financial difficulties.
German officials are investigating charges against him. Prosecutor Claudia Krauth said: "We are investigating Gemballa for insolvenzverschleppung. This relates to a person who fails to file for insolvency within a reasonable timeframe." She said German police were still probing the possibility of kidnapping and extortion.
Christiane, who has power of attorney over her husband's company, filed for insolvency on his behalf soon after he went missing. The family has hired Cape Town forensic investigator David Klatzow to help find him.