Last month, I wrote on a new report that showed the U.N. is increasingly using Private Military Security Contractors (PMSCs) for its field missions – a practice which is endangering the U.N.’s legitimacy as an organisation championing human rights, according to the author.

A number of these companies, like Dyncorp International, have been linked to a plethora of alleged human rights violations, sparking various international efforts to regulate the industry, as I reported earlier this week.

The report, published by the New York- based Global Policy Forum (GPF), recently prompted a direct responses from Greg Starr, head of the U.N. Department of Safety and Security (DSS), who wrote a letter to GFP, which the organisation published on its website this week, along with its response to the letter.

Two of the PMSCs mentioned in the report, DynCorp and G4S, (the latter having been the security provider for this year’s London Olympics) also issued statements challenging the negative portrail of PMSCs by GPF.

GPF raised concerns about post-9/11 “bunkerisation” within the U.N. – an increasing use of private security, partially fueled by involving firms directly in assessing risks and needs — as well as a lack of guidelines within the U.N. to vet contracts.

In his response to the report, Starr stated:

The fact is that there are unfortunately places in the world today where relying on the principle of acceptance does not provide the security necessary to continue operations. “Hard” security measures, which the report goes to great lengths to prove counterproductive in all instances, are actually necessary and appropriate at times.

He added that:

The overwhelming majority of contracted services for guards by the United Nations are related to residential or facility protection.

Starr admitted that “Our existing policy guidance on armed security contractors is dated, and there was a desire to address any concerns within the United Nations as to whether security companies used had requisite levels of oversight and management.” DSS has been spearheading a draft policy, he said, that “proposes a decision making framework and high standards for management accountability” for the use of PMSCs and “goes a very long way to ensuring that specific criteria was established so that the United Nations is neither tainted, impacted nor otherwise compromised by the use of these companies,” according to Starr.

GFP responded by saying it was unaware of serious policy guidance, “dated or of more recent origin” that has shaped U.N. practice regarding PMSCs and that the proposed new guidelines have not been approved and put into practice after two years of discussion.

Starr further criticised GPF for using “incomplete” data in its report.

GPF responded by quoting from an email Starr had sent to the report’s author, Lou Pingeot, during her research phase, in which the DSS chief himself declared it was impossible to know how much the U.N. spends on private security contractors annually and that he would “not hazard an estimate on an overall number.”

This lack of available statistics brings into question the ability of DSS to oversee system-wide security issues, according to GFP who in its response to Starr this week urged the DSS chief to publish annual statistical surveys of PMSC contracts.

Last month’s report, titled “Dangerous Partnership: Private Military Companies and the UN” used available U.N. procurement data to show an upward trend in the U.N.’s use of PMSCs, with a rise of 250 percent in field missions from 2006 to 2011.

While Starr emphasises the importance of PMSCs in guaranteeing security of U.N. personnel annual reports by the Secretary General on the Safety and Security of UN Personnel have failed to mention the use of private contractors and to what extend they are hired.

GPF holds that DSS is “failing in its responsibility to inform member states and the public about the UN’s security policy” and urges the U.N. to undertake a broad-ranging inquiry.

We would urge DSS to adopt a more forthcoming approach, incorporating reference to PMSCS in all reports where appropriate. Indeed, we believe that the United Nations should ask a blue ribbon panel of experts to prepare a broad-ranging inquiry into the costs, governance implications, policy impact and reputational issues posed by PMSCS. This would offer member states and the public a much-needed appraisal of these topics and lay the basis for a thorough-going review by the General Assembly.

“The U.N. [contracting system] has always been a crapshoot and it’s something we’d like to see professionalised,” Doug Brooks, President of the Washington D.C.-based PMSC trade association International Security Operations Association (ISOA), told me earlier this month.

Brooks particularly pointed to the U.N.’s penchant for late payments, which tilts the playing field in favour of large companies that can support operations while waiting up to a year for payment. “Big companies who work for the U.N. call it leaning forward — If you are a small business, there is no way you can do that.”

In addition to calls for the U.N. to improve its policies on hiring PMSCs, there are a number of international efforts underway to regulate the industry more broadly and make protection of human rights an integral part of its operations.

“I think that a key challenge for the industry is that it’s behind other industries in learning about how to integrate human rights into its strategies and operations,” James Cockayne, and expert on International Criminal Justice who has been involved in PMSC legislation efforts, told me. “It’s time that this industry caught up.”