Aman Tuleyev, the former governor of Russia's Kemerovo region in Siberia, has asked prosecutors to check and make public his incomes, expenditures, and property to prove that allegations about his "uncountable wealth" are false.
Tuleyev's office said on April 12 that opposition politician Aleksei Navalny's claim "disinforms" the public and "morally humiliates" the former governor.
On April 10, veteran Russian politician Tuleyev was elected as speaker of the Kemerovo regional legislature, eight days after he resigned as governor following a shopping-mall fire that killed 64 people.
The same day, Navalny posted on his website the findings of an investigation alleging that Tuleyev owns 12 big houses and other buildings on as many as 150,000 square meters in the region.
Tuleyev, 73, had been governor of the coal-mining Kemerovo region since 1997.
He resigned on April 1, saying it was "morally impossible" to stay on after the March 25 fire at the Zimnyaya Vishnya (Winter Cherry) mall in the regional capital -- one of the deadliest blazes in post-Soviet Russia.
Tuleyev had faced public calls to step down, including by people in a crowd of thousands who demonstrated outside his administration's office two days after the fire.
He and his subordinates were criticized over what many have seen as a callous response to the tragedy, including their characterizations of public outrage as the work of political opportunists.
Residents, relatives of victims, and Russians nationwide blamed corruption and government negligence for the high casualty toll in blaze.
Investigators said initial investigations indicated that blocked fire exits, a shutdown alarm system, and "glaring violations" of safety rules exacerbated the human toll of the fire.
Seven people have been arrested in the case, including the head of the local building-inspection agency and an executive with the firm that owns the shopping mall.