British Prime Minister Boris Johnson will not face criminal action following allegations of misconduct over his relationship with a US tech entrepreneur but he might have had an intimate relationship with her, the police watchdog said on Thursday.

The Independent Office for Police Conduct (IOPC) launched an investigation last September following a newspaper report that Johnson, when mayor of London, had failed to disclose his personal links to Jennifer Arcuri, who received thousands of pounds in public funding and places on official trade trips.

Johnson denied any wrongdoing.

The IOPC’s director general Michael Lockwood said there was no evidence to indicate Johnson influenced any payments to Arcuri or influenced her participation in trade missions.

But Lockwood said “there was evidence to suggest that those officers making decisions about sponsorship monies and attendance on trade missions thought that there was a close relationship between Johnson and Arcuri, and this influenced their decision-making”.

The matter was referred to the watchdog because Johnson was head of the mayor’s office for policing and crime, a role equivalent to a police commissioner, during his term as mayor. The Greater London Authority said it had alerted the IOPC because Innotech, Arcuri’s then company, had received £11,500 from London &a Partners, the mayor’s promotional agency, for two events.