Sipping green tea outside a café in Notting Hill, Dr Najah Al-Otaibi is scrolling through pictures of her 19-month-old daughter Victoria.

She alights upon one strikingly cute image and holds up her phone. 'She looks so much like him,' she says. 'It's the lips, they're the same.'

The 'him' in question is former Arts Minister Lord Vaizey of Didcot, a favoured son in former Prime Minister David Cameron's government.

The Mail on Sunday can reveal today that the married Conservative peer is Victoria's father – a subject on which he kept his counsel in April when approached by this newspaper after it had emerged that his name was on the child's birth certificate.

Rather mischievously, or so it seemed at the time, Dr Al-Otaibi, 42, a Middle East expert and author, included the 56-year-old politician's name on the document but not in the section marked father. That was left blank. Instead, she listed her daughter's name as Victoria Vaizey Edward Al-Otaibi – containing a reversal of Edward Vaizey.

It was something of a compromise, she says now. A father's permission is needed to be officially named on a birth certificate, which the peer simply wasn't prepared to give.

Lord Vaizey would neither confirm nor deny paternity in April. Dr Al-Otaibi was similarly unforthcoming and there the matter might have rested, as an intriguing episode that fleetingly set Westminster tongues wagging. Many people fairly assumed, given Victoria's middle names and Vaizey's non-committal response, that Vaizey was indeed the father.