The Sun reported that the ceremony at the Catholic cathedral was carried out by Father Daniel Humphreys who had given the couple pre-marriage instructions, and baptised Wilfred previous year.
Even senior members of Johnson's office were not aware of the wedding plans, they added.
"They've looked at that, said "you are a Catholic because you were baptised Catholic, your first two weddings weren't in a Catholic church overseen by a Catholic minister therefore the Roman Catholic church does not recognise those two marriages as valid".
In its report, Daily Mail said that the 56-year-old Johnson exchanged vows with Symonds, 33, on Saturday morning, becoming the first Prime Minister to marry in office since Lord Liverpool Wednesday Mary Chester in 1822.
Boris Johnson's personal phone number has been online for 15 years.
The ceremony had to be low-key: weddings in England are now limited to 30 people due to COVID-19 restrictions.
British Prime Minister Boris Johnson and his fiancée Carrie Symonds married Saturday in a small private ceremony in London, UK newspapers have reported.
The new Mrs Johnson - who has confirmed she will take her husband's surname - wore a white dress to exchange vows with the prime minister.
Earlier this month the Sun had reported that wedding invitations had been sent to friends and family for July 2022.
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Toronto is among the units that feel prepared to reopen schools, Medical Officer of Health Dr. He added, "I don't want to rush this, if it takes a couple of extra days so be it".
But dancing is advised against due to the increased risk of transmission, except for the couple's traditional first dance.
Johnson, 56, and Symonds, 33, announced their engagement in February 2020.
Their son, Wilfred, was born last April. He was married to Allegra Mostyn-Owen (from 1987-1993), then to Marina Wheeler.
Johnson's aides were not informed of the ceremony in advance.
Mr Johnson and Ms Wheeler had four children but separated in 2018.
Several politicians have congratulated the couple, including Home Secretary Priti Patel, Vaccines Minister Nadhim Zahawi and Work and Pensions Secretary Therese Coffey.
On Friday, a government ethics adviser released his long-awaited findings on the "cash for curtains" scandal in which Johnson was criticized for failing to disclose that a wealthy Conservative Party donor had paid for the redecoration of the prime minister's official residence in London.
Northern Ireland's First Minister Arlene Foster tweeted: "Huge congratulations to Boris Johnson & Carrie Symonds on your wedding today".