He was Director-General of the Nigerien Paper Transformation Enterprise (ENITRAP) from 1987 to 1998, and in 1995 became Special Adviser to Prime Minister Hama Amadou.

[3] Oumarou was appointed to the government as Minister of Trade and Industry on April 16, 1999, under the transitional military regime of Daouda Malam Wanké.

Following elections he remained in that position as part of the government of Hama Amadou (who returned as Prime Minister), which was named on January 5, 2000.

[8] Oumarou remained Minister of State for Equipment until Amadou and his government lost a no-confidence vote in the National Assembly on May 31, 2007.

[4] Oumarou's appointment was opposed by the main opposition party, the Nigerien Party for Democracy and Socialism (PNDS), as well as a number of civil society organizations, because he was so closely associated with his predecessor and possibly tainted by the same corruption scandal related to embezzlement of education funds that caused the no-confidence vote against Amadou.

[15] As the criminal prosecution of former Prime Minister Hama Amadou continued in 2008, some parliamentary leaders of the MNSD-Nassara remained loyal to the former party chief.

[20] In August 2009, a constitutional referendum providing for a three-year extension of Tandja's term was successful amidst an opposition boycott.

[24] Dissatisfied by the ongoing political crisis, the military seized power on February 18, 2010, ousting Tandja and immediately dissolving the National Assembly.

According to Ousmane Cissé, the Minister of the Interior, they were arrested because they were involved in "subversive activities and undermining of the government and the transition process".

In his new post as the President's representative, Oumarou was assigned broad responsibilities for "the conduct and management of political, economic or social projects" and was formally ranked fifth in state protocol.