There are credible fears that the charges against a well-known opposition activist in Alexandria may be spurious and have been brought in retaliation for his activism, Amnesty International said as his appeal hearing against his conviction is due to resume.

On 12 March, the activist Hassan Mostafa was convicted and sentenced to two years in prison for insulting and attacking a public prosecutor in Alexandria – accusations he vehemently denies. The original case was marred by procedural irregularities including the refusal of the trial court to hear all defence witnesses. Hassan Mostafa is currently being held at the Borg al-Arab Prison and will attend his next hearing tomorrow.

Hassiba Hadj Sahraoui Deputy Middle East and North Africa Programme Director at Amnesty International said:

“We fear that Hassan Mostafa may be imprisoned solely for the peaceful exercise of his right to freedom of expression and other human rights, in which case Amnesty International would consider him to be a prisoner of conscience and call for his immediate and unconditional release.

“The appeals court must review all the evidence in this case.”

The alleged incident took place on the morning of 21 January inside the Manshiya Prosecution office in Alexandria. Hassan Mostafa had gone there with a group of local lawyers and activists to enquire about the fate of dozens of protesters who had been arrested a day earlier during unrest following the trial of police officers accused of killing protesters during the "25 January Revolution".

About an hour after leaving the Manshiya Prosecution office, Hassan Mostafa was arrested inside the adjacent Alexandria Court complex. According to other activists present at the time, a group of riot policemen beat them with sticks as they were trying to shield Mostafa from arrest.

Colleagues of the public prosecutor Hassan Mostafa is accused of attacking led the investigations and brought the charges against Mostafa.

Hassiba Hadj Sahraoui said:

“In view of the concerns this raises about impartiality, Amnesty International believes that the interests of justice would have been better served if evidence-gathering and investigations into the alleged crime had not been conducted by prosecutors from that office.”

At his first appeal hearing on 4 May – which an Amnesty delegate attended – witnesses testified that, while a verbal altercation did occur inside the Manshiya Prosecution office, Hassan Mostafa did not slap or otherwise physically assault the public prosecutor.

At this hearing, the judge decided to postpone the proceedings until tomorrow in order to hear testimony from the prosecution witnesses. He also ordered the prosecution to present evidence linked to a hospital medical report which reportedly documents the redness of the public prosecutor’s cheek after the alleged incident – since the defence lawyers raised concerns about its reliability.

Before his recent arrest, Hassan Mostafa had been active in Egypt's opposition movement for several years. In April 2010, he was detained during a protest demanding the end of emergency laws, which the then-President Hosni Mubarak had kept in place for decades.

Amnesty fears that the charges he faces are linked to his opposition activism and, more specifically, his activities urging the Manshiya Prosecution to reveal the fate and whereabouts of individuals arrested in connection with the unrest earlier this year.

His lawyers told Amnesty they fear that additional charges are likely to be brought against him in relation to his participation in another protest, in an apparent attempt to keep him imprisoned for longer.

Hassan Mostafa’s hearing comes amid a notable increase in legal harassment of opposition activists, bloggers, comedians, protesters, and others in Egypt. Charges of insulting President Mohamed Morsi or other officials, or of “defaming” religion – as well as sweeping arrests of opposition protesters – are now the norm.