A spending watchdog is poised to launch an investigation into a Government scheme that sold prison expertise overseas.
Justice Secretary Michael Gove closed down the controversial departmental commercial body that struck deals with other countries, including some with poor human rights records.
But despite Just Solutions international (JSi) being disbanded, a controversial justice deal with Saudi Arabia remained on the table until earlier this month.
The National Audit Office is now considering launching an investigation into JSi, which was established by former justice secretary Chris Grayling in 2013, after concerns were raised about its operations.
Labour former lord chancellor Lord Falconer was among those to call on the watchdog to look into the funding of the unit and the "lack of transparency" surrounding it.
An NAO spokesman said: "The NAO received correspondence setting out concerns around the operations of Just Solutions International.
"Preliminary work is being carried out into the concerns raised."
Downing Street claimed the decision to cancel a deal to train prison staff in the Gulf state was financial and not linked to human rights concerns but Labour leader Jeremy Corbyn said the Government had been ''shamed into'' ditching the agreement.
The ambassador's article drew criticism.
Kate Higham, of human rights organisation Reprieve, said: "The Saudi Government's misconceived view seems to be that not only must Britain keep its mouth shut about their horrific abuses - we should also be actively supporting them."
She said the Saudi authorities "still don't seem to have got the message", adding: "They need to realise that until they put a stop to the horrific abuses in the kingdom, no country with any respect for human rights will want to go near their 'justice' system."