Death sentences are at a record high despite the number of executions falling by more than a third, according to a new analysis mapping the number of those put to death around the world.

The report by Amnesty International also raises concerns that Britain may be “damping down” its criticism of countries that use the death penalty as it attempts to pursue post-Brexit trade deals and enters into new security arrangements.

According to the organisation’s annual survey around 1,032 executions were carried out globally in 2016 – a 37 per cent decrease on the previous year. In 2015, 1,634 people were executed making it the highest figure recorded in a single year since 1989.

But despite the year-on-year fall of those put to death, campaigners warned the number of executions remained historically high and also found that 3,117 people were sentenced to death in 55 countries last year – a significant increase on the two previous years.

Amnesty International said this was "the highest number of death sentences ever recorded in a single year by the organisation"

In reality, however, the figures are likely to be considerably higher as in some counties, including China and Vietnam, data on the use of the death penalty is classified as a state secret. It is believed that thousands were executed in China last year but authorities are “deliberately obscuring the shocking scale of executions”.

The research adds: “During 2016 little or no information was available on some countries – in particular Laos, North Korea, Syria and Yemen – due to restrictive state practice and/or armed conflict.”

The 47-page report adds that across the world there are at least 18,848 people who were known to be under sentence of death at the end of 2016.

Of the executions recorded last year, Iran alone accounted for 55 per cent of the total figure while Iraq more than tripled its executions. In line with previous years, the organisation did not receive any reports of judicial executions by stoning but logged methods including beheading, hanging, lethal injection and shooting.

Kate Allen, the director of the organisation, also voiced concern that Britain may be toning down its criticism of countries that use the death penalty as it pursues trade deals and entering into new security arrangements.

“We fear that trade and security issues are trumping human right,” she said. “With UK officials damping down their objections to the death penalty when it comes to countries like Saudi Arabia or Bahrain.

“When, shockingly, Bahrain executed three men after deeply unfair trials recently, the Foreign Secretary could muster only the mildest of rebukes. At its best the UK does some very important work in encouraging countries to end capital punishment, but with death sentences running at record levels around the world now is not the time to go quiet on the issue.

“If governments in Beijing, Manama, Islamabad and Riyadh see there’s very little public outrage over executions, then they're going to think they’ve got a green light to carry on killing.”

Her comments also came after the Joint Committee on Human Rights in Westminster warned that human rights must form a key component of any future trade deal after Britain’s exit from the European Union.

Just last week Theresa May went on a charm-offensive of the Middle East and visited Saudi officials for talks in Riyadh to boost trade and security ties despite the regime’s dire record on human rights and its use of the death penalty.

While welcoming the overall trend towards fewer executions, Maya Foa, a director at Reprieve, added it is “disturbing that certain government’s are increasingly using the death penalty as a means of crushing dissent.

“Many of those with the worst record on executions are countries which British Prime Minister Theresa May has been actively courting in recent weeks – has been actively courting in recent weeks – including Saudi Arabia, where juveniles face beheading and crucifixion, and Bahrain, where political protesters have been executed on the basis of forced ‘confessions.’

“The UK government must not let the trade agenda trump concerns for human rights. Ms May must condemn the use of the death penalty as a tool of oppression.”

At the beginning of 2016, the oil-rich Saudi regime executed 47 people in a single day, including the prominent Shiite cleric Nimr al-Nimr, leading to widespread demonstrations.

Responding to Amnesty International’s report, a Foreign Office spokeswoman said the UK’s opposition to the death penalty is clear. “We condemn and do not support it under any circumstances.”