CAIRO (AP) — Egypt's official news agency says an investigative judge has questioned Hosni Mubarak's two sons over new corruption allegations.

The two — onetime heir apparent Gamal and wealthy businessman Alaa — are on trial for insider trading. They were acquitted on June 2 of separate corruption charges. They have been in detention since April 2011.

The latest charges arise from their 1993 purchase of a plot of land from a housing association led at the time by Ahmed Shafiq, Mubarak's last prime minister and longtime friend who unsuccessfully ran for president earlier this year.

The MENA news agency on Thursday quoted judge Osama el-Saidi as saying the two bought the land at a fraction of its market value.

Mubarak, ousted last year in a popular uprising, is serving a life sentence.