JEDDAH (AFP) - The world's largest pan-Islamic body, the Organisation of Islamic Cooperation, said its Saudi chief resigned on Monday, days after infuriating Egypt over a remark that mocked President Abdel Fattah al-Sisi.

OIC Secretary-General Iyad Madani "has resigned for health reasons", the Jeddah-based organisation said in a statement, two days after Cairo condemned the comment that provoked outrage among Egyptians.

"The OIC General Secretariat takes this chance to express its utmost appreciation and respect to all member states," the 57-member bloc said.

The former Saudi minister made the comment last week after he mixed up Sisi's name with that of Tunisian President Beji Caid Essebsi at a conference.

"Mr President Beji Caid al-Sisi. Essebsi sorry. This is a big mistake. I'm sure your fridge has more than water, your excellency," he told the Tunisian leader.

He was referring to widely derided comments made by Mr Sisi earlier last week in which he claimed that his fridge only had water in it for a decade.

Egypt's Foreign Minister Sameh Shoukry on Saturday said Mr Madani's remark was "a serious encroachment against a founding member state of the organisation and its political leadership".

"Such remarks do not conform with the responsibilities and the duties of the organisation's secretary-general position, and fundamentally affect his ability to carry out his duties," he added in a statement in English.

Mr Madani, who had headed the bloc since 2014, apologised, saying in a statement he meant no "insult to the Egyptian leadership".

Saudi Arabia has nominates its former minister of social affairs, Mr Youssef al-Utaymeen, to replace Mr Madani, the OIC statement said.