France's Interior Minister Bruno Le Roux has resigned over a "fake jobs" row involving work he gave his daughters when they were teenagers, the BBC reported on Tuesday.
Le Roux told a news conference that he felt it was his "responsibility", but denied wrongdoing.
It is alleged that his daughters were being paid for work while involved in other activities.
The Socialist minister has repeatedly insisted that the summer jobs were legitimate.
French President Francois Hollande said he had accepted Le Roux's resignation and named Trade Minister Matthias Fekl as his successor.
Centre-right presidential candidate Francois Fillon is already under investigation for employing his family.
That probe has now been widened to include possible forgery and aggravated fraud, French media report.
Investigators are looking at whether Fillon and his wife Penelope forged documents to try to justify the €700,000 ($755,000) she was given for work as a parliamentary assistant that she is alleged not to have carried out.
Fillon, initially the favourite to win the presidential election in April and May, is now running third in the opinion polls.