In a statement, the Raif Badawi Foundation said it had received the confirmation from the same source that had notified his family and associates about the first set of 50 lashes, which were served on January 9, 2015. The foundation did not specify who the source was.

In contrast to the first round of punishment, which was performed in a public place, the next lashing was reportedly due to be carried out inside prison. Following injuries after his first flogging, Badawi's remaining 950 lashes had to be postponed indefinitely.

The foundation said it had called on the Saudi government and royal family to intervene and stop the punishment. It has also asked the government to pardon Badawi and to deprive him of his Saudi citizenship, so he could be reunited with his family, who reside in Canada where they were granted asylum.

The announcement comes ahead of the Frankfurt Book Fair, where the Raif Badawi Foundation is expected to give a journalism award to a radio station based in northern Iraq.

NWE radio for refugees has been hailed for its efforts to broadcast news, with information in three languages for internally displaced Iraqis fleeing from the so-called "Islamic State" (IS) movement.

One thousand lashes against liberty

The blogger has been imprisoned since 2012 for insulting the particularly conservative interpretation of Islam practiced in Saudi Arabia with his open advocacy of free speech and freedom of religion.

His blog, the Saudi Free Liberals Forum, was shut down following his arrest. Initially handed the death penalty for apostasy, he was given a sentence of 10 years in prison and 1,000 lashes to be served concurrently.

Badawi received his first 50 lashes in January 2015, sustaining sufficient injuries for the sentence to be suspended for nearly two years. Amid the international condemnation that ensued, the 32-year-old received numerous human rights awards, including the Sakharov Prize and the BOB award, DW's recognition for Freeedom of Speech.

Badawi's wife, who is allowed to speak to him on the phone once or twice a week, said that his health had suffered considerably since he was given the sentence. Badawi has also reportedly been on sustained hunger strike on at least two occasions.