The Russian Athletics Federation (RusAF) has filed its response to charges that several of its officials obstructed an anti-doping investigation into world indoor high jump champion Danil Lysenko.
In a statement, RusAF confirmed it had sent its response to the Athletics Integrity Unit (AIU) by yesterday's deadline, which had been extended by three weeks.
The AIU has received the explanation from RusAF, but neither party has divulged any further details.
The AIU, which handles doping and disciplinary issues for World Athletics, in November accused RusAF officials of "serious anti-doping breaches" following a 15-month investigation.
The scandal toppled former RusAF President Dmitry Shlyakhtin, replaced on an acting basis by Yulia Tarasenko, and prompted World Athletics to warn it was considering expelling the embattled organisation.
World Athletics also froze the reinstatement process for RusAF and put its system of allowing Russian athletes who meet strict criteria to compete as neutrals on hold.
Shlyakhtin, appointed RusAF President in 2016, was suspended by the AIU for his involvement into whereabouts violations committed by Lysenko.
He has been accused of using fake medical documents in an attempt to ensure Lysenko avoided punishment and of failing to cooperate with an investigation.
The charges against the seven individuals associated with RusAF could impact on the country's participation in athletics at this year's Olympic Games in Tokyo.
Tarasenko claimed last month that she still expects Russian track and field competitors to participate as neutrals at Tokyo 2020, despite a series of sanctions imposed on the country by the World Anti-Doping Agency (WADA).
WADA handed Russia a four-year ban after an investigation found data from the Moscow Laboratory had been tampered with before it was handed over to the global watchdog in January 2019.
The sanctions from WADA mean Russia's flag will be banned from major events, including Tokyo 2020, while the country is also set to be stripped of World Championships it has been awarded.
WADA ruled that Russian athletes who can prove they had no involvement in the doping scandal or the cover-up will be able to compete – a condition Tarasenko claims should apply to Russian competitors in athletics.