Lagos - The former campaign chief of Nigeria's ex-president Goodluck Jonathan has been arrested for allegedly stealing $48.5 million from state coffers to fund his failed 2015 re-election bid, an official said on Tuesday.Ngozi Olojeme was head of Nigerian Social Insurance Trust Fund (NSITF) and siphoned off this amount from the fund, an official from the national anti-corruption agency EFCC told AFP."She is in our custody for an alleged fraud totally $48 485 127 belonging to NSITF," he said, and added that the EFCC had also seized 38 properties traced to Olojeme. "The properties have been placed under an interim forfeiture in line with a court injunction pending further investigation and trial," he said. Key members of the Jonathan administration have been arrested and charged with corruption by the government of President Mohammadu Buhari, who won the 2015 election. Buhari's electoral pledges included a promise to rid Nigeria of endemic corruption which has stunted its growth. Critics have accused Buhari of a witch-hunt as only members of the opposition have been targeted in the corruption campaign.