He had been a member of the Shropshire Corona Resilience Network, which has protested against lockdown regulations and the compulsory wearing of facemasks.
But fellow member Charlie Parker said his friend was a strong-willed and intelligent man, and said he had been distressed by claims that Gary had been "led astray by 'Covid deniers".
Mr Parker said the group they belonged to had never denied that the virus was real, but simply wanted to share information so that people could make an informed decision about the risks.
"Gary was a very intelligent man, he had researched a lot of information himself, we used to call him 'The Encyclopaedia' in the group because he was so knowledgeable.
"Gary was a strong-minded, very intelligent individual, he very much chose to be part of our community, and found solace in talking together with us.
"He took pride in sharing well researched information from credible sources. For this reason he was a highly valued member of our community in holding the Government to account on their inconsistent and ruinous lockdown policies.
"We are not Covid deniers – we are not saying the disease doesn't exist, or that it hasn't killed people. What we are saying is that it has been over-exaggerated to further a political agenda.
"We do not accept that putting a piece of cloth over your face will stop you from getting it, or that it will protect anybody else. We also don't believe that lockdowns work."
Mr Parker, 32, from Shifnal, said that comments had also been made about Mr Matthews not wearing a mask, but added that he had medical exemption which meant that he was not required to.