But last week, he closed the case when his client Richard Terwin returned from Cuba after meeting his dad.
Their reunion was the culmination of a five-year-long search by private detective Christian Botha, who began the case with very little to go on.
"All Richard had was a nickname, Babis Voreas, and a letter from a ship's captain allowing Richard's mother to board the ship while it was in harbour," said Botha.
Voreas had come to East London as a mechanical engineer on board a ship, just over 30 years ago. While in the coastal town, he met Terwin's mother. A romance blossomed and she fell pregnant.
But there was a problem.
"He had promised to marry someone in Greece, I think it was sort of an arranged marriage," Terwin said.
Terwin's father left East London but he wrote letters to his mother until his son was 2 years old.
At age 18, Terwin began searching for his father, and in 2003 he asked for a professional's help.
Right from the start, Botha hit dead ends: "I found out that the shipping company no longer existed, and the ship was scrapped about 15 years ago."
The years went by and Botha's luck didn't change.
Then about a year ago Botha got a lead. "A Greek friend of mine told me that Babis is short for Charalampos. I found a phone listing for a Charalampos Voreas in the Greek resort town of Kranidi."
But the phone number no longer worked.
Botha fired off hundreds of e-mails to people living in the town. He got lucky. "Out of the blue I get this e-mail, which said he knew Babis and that he was in Cuba."
Botha got a cellphone number for Voreas and dialled it. "I asked 'Are you Babis Voreas and did you have a son called Richard?'. He said yes, then started crying. He didn't want to put the phone down."
Terwin made contact with his father, and a year later made the trip to Cuba.
