THE ELECTORAL Commission has announced it will investigate the funding of refurbishments made to Boris Johnson's Downing Street flat. 

The watchdog said there were "reasonable grounds to suspect that an offence or offences may have occurred" since they began speaking to the Conservative party last month.

It comes after reports that £58,000 was paid by a donor to the Conservative Party, after which the party then paid for the work.

Boris Johnson has been plagued by allegations of misconduct over the payments since last Friday, when his former senior adviser Dominic Cummings said his plans for "secret" donations were "unethical, foolish and possibly illegal". 

No.10 has continued to insist Mr Johnson paid for the work himself, but has yet to clarify if he paid for it from the outset or if he repaid a loan from a donor or external source. 

Any donations for the revamp should be declared via the register of ministers' interests, which has not been updated since last year following the departure of the government's adviser on Ministerial Standards, Sir Alex Allan.

Sir Alex quit his role in November over the handling of the inquiry into bullying claims against Priti Patel, after he concluded she had “not consistently met the high standards expected of her” while Mr Johnson cleared her of wrongdoing. 

An Electoral Commission spokesman confirmed this morning that they would now be looking into the funding of the work at Mr Johnson's flat, above No.11 Downing Street.

READ MORE: Downing St denies Tory party funded Boris Johnson's £60k flat refurb

He said: "We have been in contact with the Conservative Party since late March and have conducted an assessment of the information they have provided to us. 

"We are now satisfied that there are reasonable grounds to suspect that an offence or offences may have occurred.

"We will therefore continue this work as a formal investigation to establish whether this is the case. 

"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. 

"We will provide an update once the investigation is complete. We will not be commenting further until that point."