Bahrain activist Nabeel Rajab (Photo: Reuters)
Prominent Bahraini activist Nabeel Rajab is believed to have been transferred from his prison cell by authorities without the knowledge of his immediate family.
Rajab's wife, Sumaya, told the BBC on Wednesday that she had been informed of her husband's removal by a relative of a fellow prisoner.
According to US-based advocacy group Human Rights First, Said Yousif, president of the Bahrain Centre for Human Rights, received a call from Rajab on 12 May, during which he claimed to have witnessed the torture of eight young men in Bahrain's Jaw Prison.
Prison authorities, however, insist that Rajab is 'okay' and remains in his cell.
Rajab is currently serving a two-year prison sentence on charges widely seen as politically motivated.
The Shia activist was jailed for criticising the country's Sunni-Muslim community via Twitter.
On Wednesday, six activists were charged with insulting King Hamad via Twitter and slapped with one-year prison sentences.