Kumar was placed under suspension after the receipt of a report from CBI in the matter.
"Following the receipt of the official report from CBI, the Ministry of Railways places Mahesh Kumar, Member (Staff), under suspension," Additional Director General of Railways, Public Relations, Anil Saxena, told PTI.
Kumar was arrested by CBI after the agency apprehended him while paying the bribe to Bansal's nephew Vijay Singla reportedly for a plum post.
Kumar's suspension came hours after the Railway Ministry issued a statement maintaining that no rules had been flouted in the appointment as Member (Staff) earlier this week.
"No officer senior to Shri Mahesh Kumar fulfilling the norms governing appointment to the post of Member (Staff) has been superseded," the ministry said.
Bansal's own continuance in the Union Cabinet hangs in alance with the Congress Core Group not reaching a conclusion on his future in the ministry. The Group will meet again tomorrow to take a call on the issue.
Bansal has, however, insisted he has no business links with Singla.
"The charge of Member (Staff) will be looked after by Subodh Jain, Member (Engineering) and of General Manager, Western Railway by R C Agarwal, who is General Manager, North Western Railway," Saxena said.