The organizations, including Human Rights Watch, said in a letter to Bahrain's King Hamad bin Isa Al Khalifa on Saturday that the Bahraini authorities should release al-Singace, who is serving life imprisonment for participation in pro-democracy protests in the tiny Persian Gulf Arab country's 2011 uprising.
In the letter, sighted by pan-Arab daily Al-Quds Al-Arabi, the human rights organizations stressed that the 60-year-old activist has been on hunger strike for a long time and is suffering from post-polio syndrome and many other health problems as he has been deprived of access to appropriate medical care.
“It is outrageous that Bahraini authorities seem to have denied Dr. Abduljalil al-Singace the medical care he urgently needs, not to mention his massively unfair 12-year imprisonment and sentencing,” said Michael Page, deputy Middle East director at Human Rights Watch.
"The Bahraini government must immediately allow al-Singace to obtain the necessary medical care and give him the consideration he deserves," Page added.
Media reports have already warned of the activist’s post-polio syndrome and several other health problems, including severe intermittent headaches, prostate problems, inflammation in his shoulder joints, tremors, numbness, and poor eyesight.
The human rights organizations "respectfully requested the immediate and unconditional release of al-Singace to ensure that he receives the necessary medical care and to protect him from torture and ill-treatment.”
The organizations expressed deep concern about the imprisoned academic’s current health condition, saying, "We are particularly concerned about the delay and denial of access to essential medicines prescribed by his doctor, including pills necessary for his nervous system and bodily functions and eye drops, in flagrant disregard of his doctors' instructions.”
Last month, the United Nations Human Rights Committee reiterated its call on the Bahraini government to release Singace as well as other unlawfully imprisoned human rights defenders, including Abdulhadi al-Khawaja and Naji Fateel.
Demonstrations have been held in Bahrain on a regular basis ever since the popular uprising began in mid-February 2011.
People demand that the Al Khalifa regime relinquish power and allow a just system representing all Bahrainis to be established.
Manama, however, has gone to great lengths to clamp down on any form of dissent.