The Duchess of York travelled to Saudi Arabia as a guest of the Crown Prince accused of ordering the savage torture and murder of a campaigning journalist – and promptly lavished praise on the nation's 'good leadership'.

The Mail on Sunday can reveal that Sarah Ferguson accepted an invitation from Prince Mohammad bin Salman to appear at a conference in the Saudi capital Riyadh earlier this month.

Both the United Nations and the CIA have named the Crown Prince – known by his initials MbS – as the prime suspect for sanctioning a 15-strong assassination squad to kill Washington Post columnist Jamal Khashoggi at the Saudi consulate in Istanbul in October 2018.

The journalist had been an outspoken critic of the ruling House of Saud regime.

Sarah, Duchess of York (pictured at the Misk Global Forum) accepted an invitation from Prince Mohammad bin Salman to appear at a conference in the Saudi capital Riyadh

But during the conference, the Duchess gushed: 'Everyone has been so nice here in Riyadh. I think that comes from good leadership.'

News of her decision to cosy up to MbS – the second most senior figure in the kingdom and whose family wealth is estimated at £1 trillion – comes as her ex-husband Prince Andrew struggles with the fallout from his disastrous TV interview about his relationship with paedophile Jeffrey Epstein.

Now Fergie also finds herself accused of poor judgment. Labour politician Ann Clwyd, who was a member of a cross-party panel of MPs who accused Saudi authorities of torturing women detainees, said: 'There are so many questions to be asked about this man [MbS]. Perhaps someone should teach the Duchess some hard facts about life in Saudi Arabia and how their policies affect so many people.

'I couldn't imagine someone like Princess Diana doing something like this.

Pictured: Sarah, Duchess of York speaks at the Misk Global Forum in Riyadh earlier this month

'It's really damaging for the Royal Family itself when one of them is involved in that.'

The invitation from MbS to attend the Misk Global Forum on November 12 was extended by Bader Al-Asaker, the head of his private office. The Misk Foundation describes itself as 'devoted to cultivate and encourage learning and leadership in youth for a better future in Saudi Arabia'.

The Duchess's spokesman insisted the 60-year-old had not been paid to attend the event, which is chaired by the Crown Prince.

But after a rambling interview, she took the opportunity to promote her brands of room infusers, flavoured teas and jewellery.

The Duchess's spokesman said that any profits from the event would be given to a children's trust that she founded with the charity Humanitas.

During an on-stage interview for which she was billed 'The Resilient Philanthropreneur', the Duchess – dressed in a khaki robe, pink headscarf and a black headband – was jokingly described as 'Sarah of Arabia' and incorrectly introduced as 'Her Highness'.

She was stripped of the title when her marriage to Andrew ended in 1996.

Addressing a half-empty auditorium, she described the Duke as a 'true and real gentleman', and said: 'The greatest day of my life was marrying Prince Andrew, the finest man, the finest father, the best person I know in the world.'

The United Nations and the CIA have named the Crown Prince (pictured) as the prime suspect for sanctioning a 15-strong assassination squad to kill Jamal Khashoggi

Pictured: Footage of one of the suspected killers, dressed in a blue checked shirt, entering the consulate shortly before Khashoggi's murder in October 2018

She also claimed to have invented the word 'philanthropreneur' – even though it was actually coined 20 years ago by the Wall Street Journal – adding: 'I'm 60 and I'm just beginning my working life. Thanks very much for staying, by the way, those of you who've stayed.

'I'm so diversified that all the old wizards of life have said to me, 'You need to only focus on one thing.' But I say, 'No, if you want to write a book, write a book. If you want to make tea, make tea.'

'But really just give your heart to everything you do. I'm an embodiment of failure and I love it. It's really cool.'

In an interview with the Arab News newspaper the following day, Fergie told a journalist: 'I love the feeling of kindness that I'm getting from the people of Saudi Arabia.'

It is a sentiment unlikely to be shared by Mr Khashoggi's fiancee Hatice Cengiz, who waited outside the Saudi consulate in Istanbul as his killers hacked up his body before flying back to Saudi in a private jet under diplomatic cover.

Jamal Khashoggi (pictured) was killed at the Saudi consulate in Istanbul in October 2018

The 59-year-old's remains have never been recovered.

Despite the clinical premeditation, some aspects of the killing bordered on farce. The killers failed to notice CCTV cameras monitoring their arrival and departure from the consulate, for example, and Turkish police quickly rumbled a ruse to send a Saudi official out in Mr Khashoggi's clothing as an attempted decoy because the 'double' failed to remove his distinctive trainers.

A total of 18 Saudis were eventually arrested, of whom 11 have been charged with murder.

The Saudi royal family, including MbS, have denied involvement, but the Crown Prince did accept in a TV interview that he bore responsibility because the atrocity happened under his watch.

After the murder, CIA analysts ruled it highly unlikely that such an act could have been taken place without MbS's agreement.

A spokesman for the Duchess confirmed that she had travelled to Riyadh as a guest of the Crown Prince.

'The Duchess is not a political figure and she is totally unapologetic about going to meet the young people of Saudi Arabia who will be a force for change in that country,' the spokesman said.

'She did not meet the Crown Prince while she was in Saudi Arabia but she did meet ministers from governments of many countries who engaged in the annual forum.'