UK’s Boris Johnson says there was “no interest to declare” regarding links with US business woman Jennifer Arcuri.
It is alleged Ms Arcuri received favourable treatment due to her friendship with Mr Johnson.
The police watchdogs are deciding whether to investigate the prime minister for a potential criminal offence of misconduct in public office while he was London mayor.
Mr Johnson said everything had been done “with full propriety”.
The allegations, first reported in the papers, claim Ms Arcuri joined trade missions led by Mr Johnson when he was mayor of London and that her company received several thousand pounds in sponsorship grants.
On Friday, the Greater London Authority’s monitoring officer referred the prime minister to the Independent Office of Police Conduct (IOPC).
The IOPC deals with complaints against police forces in England and Wales.
The reason the IOPC is involved is because the mayor of London is also London’s police and crime commissioner.
He asked if he had declared any interest, Mr Johnson said “there was no interest to declare”.
“I was proud of everything I did as mayor of London,” he added.
He also attacked Sadiq Khan; the current mayor of London, saying the Labour politician “could spend more time investing in police officers than he is investing in press officers”.