Saudi whistle-blower Mujtahid, who is believed to be a member of or have a well-connected source in the royal family, revealed that the country’s Crown Prince Mohammed bin Salman will not participate in the G20 summit after recent concerns grew about an imminent coup against him and his father in Riyadh.

“Mohammed bin Salman, the son of the Saudi king, cannot leave Saudi Arabia for the fear of a coup from inside the al-Saud family, and King Salman is not able to attend the important summit alone due to his mental status,” Mujtahid wrote on his twitter page on Wednesday.

He added that the Saudi king got a cold at the end of the holy month of Ramadan and the royal court was forced to cancel his visit to Hamburg after spending hundreds of millions of dollars.

Saudi diplomatic sources announced on Monday that the Saudi will not to attend the G20 summit due to the Persian Gulf crisis related to Qatar.

Minister of Finance Mohammed al-Jadaan will instead go to the summit, scheduled to take place in the Northern German port city of Hamburg on July 7 and 8.

Last week, Mujtahid revealed high tensions in Saudi Arabia, and said a threat of a coup to topple the king and his son is highly likely.

“Moves in the al-Saud family to oust Salman bin Abdulaziz (the Saudi king) have increased by those who support Ahmed bin Abdulaziz (the king’s brother) as they are convincing him of taking the leadership in Saudi Arabia,” Mujtahid wrote on his twitter page on Sunday.

He added that the princes who have joined the move intend to issue a statement to declare King Salman’s incompetency for continued leadership of the country and nullify his recent order that brought his son to the post of the Crown Prince.

Last month, King Salman replaced Crown Prince Mohammed bin Nayef bin Abdulaziz with his own son, Mohammed bin Salman, the deputy crown prince and defense minister.