The family of a leading Egyptian activist who has been on hunger strike for more than a month to protest his imprisonment says his health is deteriorating and that he has been transferred to hospital.

The wife of Ahmed Douma — one of the icons of Egypt's 2011 uprising — says he was taken to hospital on Saturday.

Nourhan Hefzy posted on her Facebook page a petition signed by more than 30 physicians testifying that he is "risking death." The physicians say Douma suffers severe stomach pains and is frequently vomiting.

Douma, who is serving a three-year sentence for violating a law banning street protests without police permits, started the hunger strike along with scores of other imprisoned activists to protest the law and harsh sentences on violators.