Italian investigators have received UK permission to question a Cambridge University academic over the high-profile murder of an Italian student in Egypt, Italy's foreign minister says.
Giulio Regeni's mutilated body was found dumped in the outskirts of Cairo in February 2016.
He had disappeared days before, while researching independent trade unions.
His supervisor at Cambridge was Dr Maha Abdelrahman. The nature of her role in Regeni's project is under scrutiny.
Italian Foreign Minister Angelino Alfano met his UK counterpart Boris Johnson on Wednesday, and said later that "the British judge has accepted the European investigation warrant and therefore the Cambridge tutor can be questioned".
He called it "a significant advance" in the case.
The BBC understands that Dr Abdelrahman has agreed to be questioned next month.
Egypt has denied accusations that the PhD student died in custody. However, officials have admitted that the security services were monitoring him.
President Abdul Fattah al-Sisi said "we are working in a very transparent way with the Italian authorities".
In a statement to the BBC, a spokesperson for Cambridge University said "both the university and Dr Abdelrahman are co-operating fully.
"A range of dates has been mutually agreed for Dr Abdelrahman's deposition. We strongly reject any suggestion that Dr Abdelrahman has deliberately postponed or delayed her testimony."
She is an expert on protest movements in Egypt. She was a professor of sociology in Cairo before joining the Cambridge Centre of Development Studies in 2007.
Italian investigators want to examine her phone data for the period January 2015-February 2016, Italian media report.
Letter of support
In an open letter published in the Guardian newspaper on Sunday, 344 academics expressed support for Dr Abdelrahman, and said "there is overwhelming evidence that strongly implicates the Egyptian security forces in Giulio's murder".
They condemned the way the Italian newspaper La Repubblica reported Dr Abdelrahman's involvement in Regeni's research.
"Neither Giulio nor Dr Abdelrahman were responsible for his death in any way," they wrote.
Hundreds of people have disappeared in Egypt - and many have been tortured - in a government crackdown on political opponents.
A lawyer who investigates those disappearances, Ibrahim Metwally Hegazy, was arrested at Cairo International Airport in September and remains in custody.
He had been due to fly to Geneva for a UN meeting where he was to speak about the Regeni case and others allegedly linked to the Egyptian police crackdown.
Dr Anne Alexander, an expert on Egyptian labour protests, said that "at the moment there are clear signs that activists in the workplace trying to organise protests - whether in independent unions or not - are very much subject to repression.
"The new law on trade unions makes it almost impossible to form independent unions," she told the BBC.
During the Arab Spring of 2011 workers' strikes contributed to undermining Hosni Mubarak's regime, she said.
But after Gen Sisi's takeover in 2013 "the brunt of the repression was against the Muslim Brotherhood and left-wing and liberal activists".