Sheikh Abdullah bin Ali Al Thani was previously portrayed by Saudi Arabia and the UAE as an alternative to the Qatari leadership amid the major diplomatic dispute.
In an audio recording from January 15 obtained by Al Jazeera, Sheikh Abdullah said the rift was triggered by the Saudi and Emirati crown princes, whom he accused of plotting to take Qatar's wealth by force.
"The [Persian] Gulf crisis is based on interests and the desire of both Mohammed bin Zayed and Mohammed bin Salman to usurp the wealth and riches of Qatar," the sheikh said, referring to the Abu Dhabi and Saudi crown princes respectively.
"I urge my fellow Qataris to defend your position," he added, warning his countrymen that the two crown princes "may blind you with money to destroy your own country".
He went on to blame Mohammed bin Zayed "for the pressures on me, my confinement, and inability to return home (Qatar) or join my family, namely my two daughters", and added: "I have decided to end my life with the aim of preventing any harm to others."
Majed al-Ansari, a professor at Qatar University, told Al Jazeera that the recording came as "no surprise".
"We know that [Sheikh Abdullah] has been pressured in the past couple of months," he said. "He hasn't been as visible as he was in the beginning of the crisis, which tells us basically that he wasn't cooperating with his captors."
"There's nobody better situated than Sheikh Abdullah to talk about what Mohammed bin Zayed and Mohammed bin Salman really want as he was their partner during this crisis," added Ansari.
"He was in on everything; he was part of attempts against Qatar through this design to be the replacement of the Emir [Sheikh Tamim]. But it was clear that there was only so much that he could do when it comes to bad things he could say about Qatar."
On January 14, Sheikh Abdullah had released a video statement, saying he was a "prisoner" in the UAE, and that if anything happened to him, "Sheikh Mohammed" is responsible.
While he did not specify, Sheikh Abdullah appeared to be referring to Abu Dhabi's crown prince.
Abu Dhabi denied detaining Sheikh Abdullah.
On Wednesday, he flew to Kuwait where he was transferred to a hospital shortly after his arrival in a wheelchair.
A day earlier, Abdullah's brother, Sheikh Khalid, told Al Jazeera that his sibling's health had deteriorated due to exhaustion and pressure he was exposed to under Emirati authorities.
Sheikh Khalid had added that his brother was in stable condition and should be leaving the hospital soon.
After Saudi Arabia, the UAE, Bahrain and Egypt imposed a land, sea and air blockade on Qatar in June, Sheikh Abdullah appeared frequently on Saudi and UAE television programmes expressing his views in support of the measures against Doha.
Sheikh Abdullah was residing in Saudi Arabia since the blockade began.
The Saudi-led group of countries accuse Qatar of supporting "terrorism", an allegation Doha strongly denies.
(Photo: economictimes)