The Electoral Commission has announced it will investigate the refurbishment of Boris Johnson’s Downing Street flat, saying it was “satisfied that there are reasonable grounds to suspect that an offence or offences may have occurred”.
The election and donations watchdog said it had been in contact with the Conservative Party on the matter since March.
In an official statement, the body said: “We are now satisfied that there are reasonable grounds to suspect than an offence or offences may have occurred.
“We will therefore continue this work as a formal investigation to establish whether this is the case.”
It continued: “The investigation will determine whether any transactions relating to the works at 11 Downing Street fall within the regime regulated by the commission and whether such funding was reported as required.”
The Electoral Commission has said it will not comment further until its investigation is completed.
Johnson and his fiancee Carrie Symonds reportedly spent £200,000 of Cabinet Office money refurbishing their official apartment last year that was later paid using Tory Party donations.
Questions have been mounting for Johnson since former aide Dominic Cummings accused him of wanting donors to “secretly pay” for the renovations to his No 11 residence in a “possibly illegal” move.
Downing Street has refused to say whether Johnson received an initial loan from the Conservative Party to cover renovations to the flat at No 11.