The research, by Capacity Global, was to be debated at an event held at the House of Lords last night and attended by Trevor Phillips, chair of the Commission for Racial Equality.
The findings show that BME groups perceive the environmental sector as institutionally racist and predominantly white and middle class in its recruitment and strategic policies.
Maria Adebowale, the founder and director of Capacity Global, told Third Sector: "If you look at health or housing, you will see a diversity in their staff and beneficiaries. But the environment sector is not perceived as diverse - this has an impact on its ability to take on issues related to diversity and BME concerns."
This view was endorsed by Tom Flood, chief executive of BTCV, which audits its own employee profile.
He said: "I think the proposition is absolutely true. I'm dismayed that there are not commitments, at the most senior levels of these organisations, to a diverse workforce."
He added that a fear of "doing the wrong thing" was at the root of many organisations' reluctance to engage with the BME community.