The trial of prominent Bahraini human rights activist Nabeel Rajab – president of the Bahrain Centre for Human Rights – has been postponed for a fourth consecutive time to enable the country’s high criminal court to hire a cybercrime expert to verify who manages his Twitter account.

A new trial date has been set for 15 December.

“Nabeel Rajab’s continued detention is clearly aimed at silencing him and punishing him for expressing his views. The reopening of his case seems to confirm the political motives behind Rajab’s prosecution. He should be released immediately and all charges must be dropped,” Melody Patry, senior advocacy officer for Index on Censorship, said.

BCHR said in a statement that the latest postponement “throws a light on the lack of evidence of any wrongdoing” by Rajab.

It continued: “Rajab is being prosecuted in relation to tweets and retweets about torture in Jau Prison and the human rights violations in the war on Yemen. The prosecution of Rajab is based on Articles 133, 215, and 216 of Bahrain’s Penal Code over charges of ‘false or malicious news, statements, or rumours,’ ‘offending a foreign country’ (Saudi Arabia), and “offending a statutory body” – for which he may be sentenced to up to 15 years in prison.”

On 13 June 2016, Rajab was taken from his home. He was charged the next day and – on orders of the court – has remained in custody since while awaiting his trial, despite recurring health problems for which he was briefly hospitalised in late June after 15 days in solitary confinement.

His trial was initially due to take place on 2 August but was first delayed until 5 September, and then 6 October, 31 October and now 15 December.

Rajab served two years in jail between 2012 and 2014 for taking part in protests in the country.