Saudi Arabia ramped up executions in the first half of 2021 following a drop during its term as G20 president in 2020, Amnesty International said.
According to the rights group, the kingdom executed at least 40 people between January and July 2021 - more than during the whole of last year.
Although Saudi Arabia executed a record 185 people in 2019, the state-backed Human Rights Commission said in January that the kingdom had reduced the number of executions by 85% in 2020 compared with the previous year, putting the number for 2020 at 27.
Amnesty said executions had resumed immediately after Saudi Arabia handed over the presidency of the Group of 20 rich nations to Italy, with nine people executed in December 2020 alone.
"The brief respite in repression coinciding with Saudi Arabia's hosting of the G20 summit last November indicates that any illusion of reform was simply a PR drive," said Lynn Maalouf, Deputy Director for the Middle East and North Africa at Amnesty International.
According to the rights group, executions took place following convictions in "grossly unfair trials, marred by claims of torture during pre-trial detention leading to forced 'confessions' which the prosecution systematically failed to investigate."
This included the June 2021 execution of a man for offences rights groups say he allegedly committed while under the age of 18, although the kingdom has said it has abolished death sentences for many childhood crimes.
In the report, Amnesty also said there had been an increased crackdown on human rights activists and dissidents.
It referred to the cases of 13 activists who were prosecuted, sentenced or had their sentences ratified after what Amnesty said were grossly unfair trials before the Specialised Criminal Court (SCC).
At least 39 individuals are behind bars for activism, human rights work or expression of dissent in Saudi Arabia, according to Amnesty.