The University of Oxford has been criticised after it emerged that one in three of its colleges failed to admit a single black British A-level student in 2015.

The Guardian reports that 10 of Oxford’s 32 colleagues didn’t award places to any black students in 2015, while one – Oriel College – only offered one place in six years.

The statistics, requested by Labour MP David Lammy, formed part of a larger dataset from both Oxford and Cambridge which showed that just 1.5% of all offers from the two universities went to black students.

“Difficult questions have to be asked, including whether there is systematic bias inherent in the Oxbridge admissions process that is working against talented young people from ethnic minority backgrounds,” said Lammy, who accused the university of “social apartheid”.

Oxford argued that offers to black students had more than doubled since 2010, although those figures include other minorities including Asian students.

A spokesperson for the university said: “We’re also working with organisations such as Target Oxbridge and the newly formed Oxford black alumni network, to show talented young black people that they can fit in and thrive at a university like Oxford. All of this shows real progress and is something we want to improve on further.”