Mitrofanov, who twice ran for Moscow mayor, was expelled from A Just Russia for voting in favor of Medvedev's candidacy as prime minister.
Alexei Mitrofanov, the flamboyant lawmaker and author, will likely be given a leadership position in the State Duma on Friday amid bribery allegations against him.
The chairmanship of the committee to oversee mass media would be a feather in the cap of Mitrofanov, whose eclectic biography includes being an ex-member of two political parties, the author of a book about pop duo Tatu and an atomic energy official. Earlier this year, he was accused by a Moscow businessman of being involved in a bribery scandal.
Mitrofanov, 50, is expected to win the chairmanship of the newly created media committee in a vote Friday with the support of lawmakers from the ruling United Russia party.
A Just Russia, Mitrofanov's former party, says he is being rewarded for having backed measures favored by United Russia, including Dmitry Medvedev's candidacy for prime minister in May, which A Just Russia opposed.
Mitrofanov, who, together with three other Just Russia members, supported Medvedev's nomination, was expelled from the party for voting against party lines soon after the vote. The party could not kick him out of the faction due to parliamentary rules.
If he wins the post of media committee head, Mitrofanov will become the first de facto independent politician to chair a committee in the current Duma.
Duma Speaker Sergei Naryshkin announced the creation of the committee to oversee media issues last week. He explained the need for it by pointing to the increased attention paid to mass media, the use of new technologies by journalists and a range of new laws regulating media outlets.
Mitrofanov is known for craving media attention and is a frequent guest on talk shows about show business. He wrote a book on pop group Tatu that was used as the basis for a film about the band made by award-winning British director Roland Joffe in 2009.
Mitrofanov is also the son of a top Soviet economic official and has a background in foreign policy. He worked briefly for the International Atomic Energy Agency in Vienna in the 1980s.
He also said he would invite Deputy Leonid Levin, another former Just Russia member who was expelled from the party for supporting Medvedev's candidacy for prime minister.
The nationalist Liberal Democratic Party, of which Mitrofanov was a member before leaving in 2007 after a public scandal involving party leader Vladimir Zhirinovsky, said it would support his nomination to the post.
A Just Russia party functionary and former Duma Deputy Oleg Finko said that by making Mitrofanov the head of one of the Duma's key committees, United Russia will be able to count on him for support.
"He would be able to resolve issues on behalf of the party," Finko said.
Finko, himself a former Liberal Democrat who knows Mitrofanov well, said the post of committee head will likely be used by Mitrofanov to secure a senior position in the state-run media industry.
But Mitrofanov's opponents from A Just Russia and the Communist Party are working hard to prevent him from winning the committee chairmanship, citing an accusation that he was involved in receiving bribery money.
The accusation was made by Moscow businessman Vyachaslav Zharov, who said Mitrofanov acted as a go-between for Zharov's former business partner, who Zharov said was trying to extort money from him amid an arbitration court battle.
Zharov said a group of middlemen including Mitrofanov approached him offering to settle the court case in exchange for $200,000.
Izvestia reported that police, acting on Zharov's complaints, arrested several men, including Mitrofanov, in a Moscow hotel room on May 12, when the first installment of the bribe, $70,000, was paid.
Mitrofanov was freed because of his parliamentary immunity, Zharov told the newspaper.
Mitrofanov has denied wrongdoing and said he doesn't know Zharov. He told Kommersant in an interview earlier this week that Zharov was making his accusations on behalf of A Just Russia.
On Wednesday, Zharov addressed a letter to Naryshkin saying that Mitrofanov should not become the head of the media committee.
Members of the Duma's ethics commission will ask the Investigative Committee, the Prosecutor General's Office and police to seek more information regarding the case, Interfax reported Thursday.
Ethics commission head Vladimir Pekhtin, a senior United Russia deputy, said details of the case will be received within a month.
"At the moment, we do not have any reason to stop his work," Pekhtin said, Interfax reported.