- Day rates peaking at $1 000 - about R6 000 - quickly turned post-Saddam Hussein Iraq into a modern day Klondike for private security firms, but a growing number of hired guns are paying the price in blood.
In the latest incident to shake the industry, a Japanese former legionnaire working for a British security firm was believed to have been captured by Ansar al-Sunna, one of the most feared Islamist militant groups operating in Iraq.
Akihiko Saito went missing during a fierce fire fight that broke out when his convoy was ambushed on a perilous supply route west of Baghdad. Several were killed and others wounded among the convoy's security staff and Ansar al-Sunna later posted pictures of Saito's identity card, saying they were holding him.
Few details were available on the incident, but security sources said Saito and his colleagues were probably on an escort mission of the kind that has been widely outsourced by the US military in Iraq.
50 000 private security contractors
According to the interior ministry, there are up to 50 000 private security contractors in the war-torn country.
Estimates vary on the proportion of foreigners, but with anything between 12 000 and 20 000 men, they are the US-led coalition's second largest armed contingent, easily outnumbering British troops.
Although none of them are supposed to be involved in combat operations, a recent string of deadly attacks by insurgents has highlighted the dangers encountered by Iraq's military freelancers.
Two US security guards working for CTU Consulting were killed when a car bomb struck their convoy on a busy central Baghdad street on Saturday.
A South African working for Erynis was shot dead in an ambush in northern Iraq four days earlier.
Six US citizens employed by the Blackwater Security Consulting firm and two Filippino guards were among 11 killed when a Bulgarian commercial helicopter was shot down on April 21 north of Baghdad.
Scores also met a brutal end on Baghdad's infamous airport road, a 12km ride known as the deadliest stretch in Iraq.
According to Iraq Coalition Casualties, an independent website that tracks deaths in the war-torn country, 234 foreign contractors have been killed and accounted for since the March 2003 invasion.
Deaths remain unreported
But several sources in the private security industry admit many deadly attacks probably remained unreported.
"We get internal reports and there are often deaths that don't make it in the media. It's an industry that doesn't communicate and secrecy is one of the reasons we're here," said one on condition of anonymity.
Unprecedented outsourcing has allowed the US military to ease the pressure on troops already stretched by several wars and is seen as a way of keeping body bags away from the public eye.
"If you don't get shot on the airport road or a busy area but instead die in an ambush on an open supply route in a remote corner of northern or western Iraq, there's a good chance the news won't come out," the industry source added.
The huge contingent of foreign security guards is a ragtag army of former elite troops, retired cops, mercenaries with shadowy track records and soldiers who served in Iraq and ditched the uniform after being rotated out to quadruple their wages.
Their omnipresence has been a bone of contention for Iraqi officials.
In one of the last decrees issued by former US overseer Paul Bremer in June 2004, he granted immunity from prosecution for private security contractors working with the Americans and US-backed Iraqi government.
Bremer himself was famously protected by private security rather than the US military and much of Iraq's infrastructure and institutions depends on these firms.
There are no accurate figures on how much of Iraq's multi-billion dollar aid package is siphoned directly into security.
Gregg Nivala, regime crimes liaison working out of the US Embassy in Iraq, explained for instance how two million of the nine million dollars budgeted to exhume a mass grave in the southern Muthanna province would be paid to a private security firm to guard the diggers.
- 174 War & Disaster Profiteers Campaign