The International Cycling Union (UCI) has rejected a proposal from the French Anti-Doping Agency for collaboration with the doping controls for Paris-Nice, which begins on March 7.
In a letter to the head of the French Anti-Doping Agency (AFLD), Pierre Bordry, McQuaid said, "I do not think your proposal will lead to an improvement in the fight against doping.
"According to the World Anti-Doping code, international sporting events have to be controlled by the International Federations.
"That is the case for Paris-Nice, that will fall under the UCI's guidance. The UCI has planned to carry out 95 anti-doping tests."
The two agencies had a falling out which erupted last October when the AFLD released a report that accused the UCI of giving preferential treatment to race winner Alberto Contador's Astana team. The UCI responded saying the report was "unfounded", and in the future would seek a "neutral" partner for doping tests carried out in France.
McQuaid continued: "Do you think it would be appropriate to accept this proposal since multiple attempts have shown that we can fear from such a collaboration with AFLD?
"Such as: the lack of random out of competition tests in France"
The UCI President confirmed that they had performed 190 out-of-competition tests in the run up to the 2009 Tour de France, with the French agency only having 13, six of which were on French riders that they had access to all year around.
Last month, the UCI openly rejected the possibility of working with the AFLD in the future, which would also include the Tour de France in July.
"The AFLD's unilateral decision to conduct an informal observer programme, with the unfortunate result of an untimely, incomplete, misinformed and inaccurate report is puzzling and disappointing. It calls into question the motives of AFLD," the UCI reasoned in an earlier statement.
"Now that the Tour is over, it is even more evident that Astana received absolutely no special treatment, except in the sense of their riders being subject to considerably more doping controls than other riders," they continued. "In fact the top individual Astana riders received more than three times the number of tests of most other riders in the race."
McQuaid explained while he was at the Tour Down Under that they would now look towards working with the World Anti-Doping Agency (WADA) in the future: "Employees of WADA will work during the Tour and accompany the UCI inspectors."