South African police said Tuesday they had arrested six people for kidnapping a Dutch man who was lured to Johannesburg by an Internet scam promising a lucrative scrap metal deal. The suspects -- two South Africans and four Nigerians -- allegedly placed an Internet ad for a 42-million-rand ($6.1-million, 4.4-million-euro) scrap metal deal, then kidnapped the Dutch consultant when his company sent him to investigate, holding him hostage in a Johannesburg house. \"The suspects phoned Holland, demanding a ransom of $50,000. Eventually, they were paid $15,000 through a UK account. The victim was dropped off at OR Tambo Airport (in Johannesburg) after the ransom was paid,\" South African national police said in a statement. The arrests came after police staked out the house where the man had been held, the statement said. Three of the suspects will appear in a Johannesburg court on Tuesday and three on Thursday, it added.