Prominent Egyptian journalist and human rights advocate Hossam Bahgat is seen at a court in Cairo
Prominent Egyptian journalist and human rights advocate Hossam Bahgat (C) is seen at a court in Cairo, March 24, 2016.

Years-long travel bans and asset freezes against some of Egypt's most prominent activists are being used to muzzle civil society and are exacting lasting damage on the personal lives of those targeted, according to two reports by human rights groups.

Researchers say it is impossible to estimate the number of people affected by the measures, which are often open-ended and imposed without official notification.

There has been a sweeping crackdown on Islamist and liberal dissidents in Egypt under President Abdel Fattah al-Sisi, who as army chief led the overthrow of the Muslim Brotherhood's Mohamed Mursi in 2013 and was elected to the presidency a year later.

Egypt's state information service did not respond to a request for comment.

Sisi and his supporters say security measures taken over the past nine years were necessary to stabilise Egypt and that they are working to provide basic rights such as jobs and housing.

The cases of 15 people affected by travel bans including women's rights activists, researchers and lawyers, were highlighted in a report by U.S.-based Human Rights Watch (HRW) and London-based rights group FairSquare published on Wednesday.

A separate report by the U.S.-based Freedom Initiative and Tahrir Institute for Middle East Policy, published on Tuesday, said travel bans were often politically motivated, applied in an arbitrary fashion, and provided no recourse for challenge.

"Egyptian authorities are using travel bans as yet another tool in an arsenal of repression," said Allison McManus, research director at the Freedom Initiative.

Dozens of those arrested in the crackdown have recently been amnestied or freed from pre-trial detention, though rights groups say thousands remain jailed.

Some travel bans against activists caught up in a 2015 case investigating foreign funding of non-governmental organisations were dropped, but others remain in place. Eleven people in the case still have their assets frozen, HRW said.

The HRW report cited several activists linked to the Egypt Initiative for Personal Rights (EIPR), one of the country's most prominent rights groups, who are still banned from travel, including founder and director Hossam Bahgat and Patrick Zaki, a researcher arrested then released after writing about discrimination against Egypt's Coptic Christians.

It also cited the case of Waleed Salem, a graduate researcher of Egypt's judiciary who has been separated from his 13-year-old daughter for four years, and lawyer Nasser Amin, who it said was prevented from visiting the International Criminal Court in April to represent victims of the war in Darfur, because of a travel ban under the NGO case.

(Editing by William Maclean)