The Constitutional Court on Wednesday unanimously removed Prime Minister Yingluck Shinawatra from office, and nine of her cabinet ministers, because the transfer of Thawil Pliensri was illegal.
It ruled that she was no longer qualified under Sections 266-268 of the Constitution.
It ruled on the second of the three points at 1.34pm on Wednesday.
The 10 individuals whose caretaker status has ended are: Yingluck, Surapong Tovichakchaikul, Chalerm Yubamrung, Kittiratt Na-Ranong, Santi Prompat, Anudith Nakornthap, Siriwat Kachornprasart, Pracha Promnok, Yutthasak Sasriprapa and Plodprasop Suraswadi.
The court did not accept a petition for it to decide on a new prime minister, ruling it was not within its jurisdiction.
The case was filed by a group of senators led by appointed senator Paiboon Nititawan. They asked the Constitutional Court to decide Ms Yingluck's prime ministerial status after the Supreme Administrative Court on March 7 ruled her decision to transfer Mr Thawil in 2011 had been unlawful and unfair because she had not given appropriate reasons for his removal.
The Supreme Administrative Court ordered that Mr Thawil be reinstated.
Following Mr Thawil's removal 2011, then police chief Pol Gen Wichean Potephosree replaced him. Pol Gen Priewpan Damapong, a relative of Ms Yingluck, succeeded Pol Gen Wichean as police chief.
On Tuesday, the Constitutional Court heard testimony from Ms Yingluck, Mr Thawil, Pol Gen Wichean and Senator Paiboon.
Mr Paiboon told the court that Ms Yingluck had abused her authority by transferring Mr Thawil to open the way for Pol Gen Priewpan to become national police chief.
Ms Yingluck, who was first sworn in as premier with her first cabinet by His Majesty the King on Aug 10, 2011, insisted the transfer complied with the law, saying she did nothing wrong in exercising her administrative authority to transfer the NSC chief.
She said she did not abuse her authority because she was legally authorised to transfer state officials.
"I would like to deny all allegations I am accused of," Yingluck testified Tuesday. "As the prime minister, I am entitled to carry out responsibilities I have toward the people ... and for the utmost benefit of the general public."