At issue is whether FIFA has made every effort to contact Grigory Rodchenkov, the Russian whistle-blower and former director of the Moscow laboratory for drug testing whose testimony unmasked a vast doping program that corrupted global sports across several Olympics, with evidence extending from 2011 to 2015.

FIFA said it initially tried to contact Rodchenkov last year through WADA but was told he was not available. In a statement Tuesday, FIFA said it was awaiting the reanalysis of the samples of Russian athletes who were implicated by a trove of data obtained from Moscow in November before trying to re-establish contact with Rodchenkov. The reanalysis of the doping samples, expected to happen later this month, may be necessary to establish further evidence to successfully discipline athletes. The lab in Switzerland that is conducting the analysis is giving priority to samples from the tainted 2014 Winter Olympics before the Winter Games next month in South Korea.

“FIFA will continue its investigations, working in close collaboration with WADA and exploring every possible avenue,” FIFA officials said in the prepared statement.

James Walden, a lawyer for Rodchenkov, said FIFA officials had never gotten in touch with him.

Tygart said that was unacceptable. “Frankly, it’s exasperating. Clean athletes and the public deserve to have the impact of Russian doping on football, if any, resolved immediately. We are over three years into dealing with this mess and there is no excuse for FIFA failing to contact the star witness at this point,” Tygart said Tuesday.

Rodchenkov is currently in hiding in the United States. His testimony ultimately led to the International Olympic Committee’s decision in December to ban Russia’s Olympic Committee from next month’s Winter Olympics. After conducting their own investigation, the I.O.C.’s investigators surmised that Rodchenkov, branded a traitor in Russia, had largely been telling the truth.