Human rights activists in Egypt say the publisher of a recent book supporting Mohamed ElBaradei has been arrested.

Mr ElBaradei, the former head of the International Atomic Energy Agency, has recently returned to Egypt and launched a campaign for political reform.

He is emerging as a potential challenger to Hosni Mubarak, who has been in power for nearly three decades.

The Arab Network for Human Rights said that Ahmed Mihanna's office was raided and his computer confiscated.

Mr Mihanna is also a blogger.

A number of other activists supporting Mr ElBaradei have been briefly detained.