Egypt's former top auditor, who was sacked after highlighting government corruption, has gone on trial accused of spreading "false news", BBC News reports.

Hisham Geneina was fired in March, soon after estimating corruption cost Egypt $67.6bn over four years.

Geneina said the figure was based on an exhaustive study, but a presidential commission concluded that he had misled the public with "foreign" help.

The former judge denies the charges and says they are politically motivated.

Critics say the prosecution raises questions about President Abdul Fattah al-Sisi's avowed commitment to fighting corruption.