The Growing Media Association says there is no "causal link" between the deadly Legionella longbeachae and potting compost, following three alleged cases of Legionnaires' disease caused by compost in Scotland.
The GMA said: "It should be noted that no causal link has been irrefutably established and the microbe is also known to be native to freshwater environments. The microbe can be found in soil, compost heaps and water inside and outside the home. Over the past 10 years the UK public have used around 750 million bags of compost with no other similar incidents recorded.
"Although any risks appear to be minimal the Growing Media Association is consulting with medical advisors to better understand the science around this issue and assess whether there is any causal connection. The Growing Media Association is also working with Trading Standards to formulate some common sense advice to be printed on bags."
The cases of Legionella longbeachae disease were said to have occurred between 2008 and 2009.
It is thought the victims inhaled the disease through droplets of water in the compost.
They are the first cases of Legionnaires' disease linked to gardening in the UK.
However, the disease has previously been linked to gardening or potting mixes in Japan, the Netherlands, Switzerland and the United States.
Legionnaires' disease is usually associated with contaminated water and air conditioning systems.
Environmental health experts have said the cases underline the need for warning labels on potting soil, and that doctors should be alert for Legionnaire's symptoms among gardeners.
The report was published in the Eurosurveillance journal.