An internal investigation found that Saikawa and other executives had received improper compensation, Reuters reported on Thursday, raising doubts about Saikawa's pledge to improve governance in the wake of former Chairman Carlos Ghosn's arrest last year for alleged financial misconduct.
"It's not going to happen. I don't think it will," one of the sources said when asked if Saikawa could resign to take responsibility for the alleged misconduct.
"There's no illegality," the source said, declining to be identified because the information has not been made public.
Nissan was not immediately available to comment.
Saikawa apologised on Thursday and vowed to return any improperly paid funds as he admitted to Japanese reporters that he had wrongly received stock-related compensation under "a scheme of the Ghosn era".
The improper payments, including tens of millions of yen Saikawa received through a stock appreciation rights scheme, were disclosed on Wednesday at a meeting of Nissan's audit committee, Reuters previously reported.
Nissan's board, which is due to meet on Monday, is expected to discuss potential disciplinary action.
(Reporting by Maki Shiraki; Writing by David Dolan; Editing by Himani Sarkar and Muralikumar Anantharaman)
