Nwuche, who served at the lower legislative chamber between 1999 and 2003, was detained after responding to an EFCC invitation on Monday.
The suspect, who also served as the Deputy National Chairman of the Peoples Democratic Party under the leadership of Alhaji Bamanga Tukur, allegedly got three contracts from the Kingsley Kuku-led Presidential Amnesty Office.
Detectives at the EFCC however told Punch that Nwuche, who had since defected to APC, allegedly helped Kuku to launder N2.8bn under the guise of sending ex-militants for training in 2012.
A source at the EFCC said, “Nwuche is being investigated over an alleged N5.6bn contract which his company, Foundation For Youth Development, allegedly received from the Kuku-led Presidential Amnesty Office.
“He allegedly got three contracts from the Amnesty Office in 2012 for the training of ex-agitators in Malaysia. Up till now, nothing was done about the contract yet, he collected N2.8bn,” an source said.
According to detectives, the cash was allegedly laundered through companies, individuals and bureau de change operators back to Kuku, through a front who is also being investigated by the EFCC.
As of 8pm on Monday, Nwuche was still being quizzed by EFCC detectives.
Meanwhile, EFCC is still investigating Kuku, who was a Special Adviser to ex-President Goodluck Jonathan on Niger Delta Affairs.
Kuku, who is believed to be hibernating in the United States, was invited by EFCC for questioning sometime last year but failed to honour the invitation.