A Nigerian anti-corruption agency has begun investigating former ministers alleged to have taken bribes from the German telecoms firm, Siemens.
Siemens was found guilty of paying bribes and was fined 201m euros ($248m) by a Munich court on 4 October.
Names on the court papers that emerged last week included Bello Mohammed Haliru, the late Haruna Elewi and Tajudeen Olanrewaju
Siemens has been fined 210m euros ($248m; £145.5m) by a German court following an investigation over whether workers paid bribes to gain contracts.
Siemens also agreed to pay 179m euros to the tax authorities, after a failure to declare payments properly
Two former Siemens managers have been convicted by a German court of their involvement in paying 6m euros (£4.1m; $8m) in bribes to win contracts.
Andreas Kley, 63, received a two-year suspended sentence for bribery and breach of trust, while Horst Vigener, 73, was given nine months’ probation
Thousands of workers at the engineering giant Siemens have staged rallies throughout Germany in protest against the threat of jobs moving abroad.
“Staff have been told to work 40 hours instead of 35 a week for the same pay or else production will go elsewhere,” a union official told BBC News Online.
Hartwig Oertel of IG Metall said staff walked out of their factories on Friday and held rallies for an hour or so