A court in Egypt has banned the Muslim Brotherhood from carrying out any activities and has ordered the confiscation of its assets.
The interim government has taken a series of tough measures against the group since President Mohammed Morsi was deposed by the Army on 3 July.
The Brotherhood has since spearheaded opposition to the new government.
Hundreds of its supporters were killed and many more were arrested when Egyptian security forces broke up mass protests. Dozens of its leaders are in detention.
The Brotherhood was founded in 1928 and was banned in Egypt from 1954 until President Hosni Mubarak was overthrown in 2011.
Following Mr Mubarak's ousting, the Brotherhood launched its own political party, the Freedom and Justice Party.
The BBC reports Monday's ruling was issued by the Cairo Court for Urgent Matters, which did not reveal the grounds for its edict.