The veteran Spaniard claimed the test fell between a steady stream of negative results.
The 36-year-old left hander, ranked No.58 in the world, said he had isolated in August after an asymptomatic diagnosis.
He said he then underwent "multiple" tests including in Rome and Hamburg, all of which were negative until he tested positive in the French capital on Tuesday.
"I explained my history to try and get another test especially seeing what had happened to other players in similar cases," former world number seven Verdasco said in a statement.
"Roland Garros refused to do another test even taking into account all these circumstances and that there were enough days to repeat the tests before the competition and draw ceremony.
"Still I was disqualified."
Verdasco said on Friday (AEST) he did two more tests on his own account and they were again negative.
"This could happen to any player and in my opinion we should at least be granted the chance to do new tests and avoid unfair disqualification.
"I want to communicate my total frustration and outrage with the organisation of Roland Garros for taking away my right to participate without giving me the opportunity... to confirm that the result of the first test could be an error."
Last Sunday, the French Tennis Federation said five players due to take part in men's qualifying had been stood down.
Two had tested positive while three others had been in contact with a coach who had also returned a positive test.
One of the five players was former top 30 Bosnian Damir Dzumhur who was forced to quarantine after his coach Petar Popovic tested positive.
"We're sure it was a false positive because my trainer has anti-bodies," Dzumhur wrote on Instagram.
"He was not allowed to take a second test. I am devastated."
The other players were named in Spanish media reports as Ernesto Escobedo from the United States, Uzbekistan's Denis Istomin, Bernabe Zapata Miralles from Spain and Serbia's Pedja Krstin.
Popovic told L'Equipe it was a "scandal" and had "(Rafael) Nadal been in our shoes, he would have had the right to a second or third test".
This year's French Open, already delayed by four months because of the pandemic, gets underway in Paris on Sunday.