This article is more than 11 months old

This article is more than 11 months old

Boris Johnson could be summoned by the London assembly after failing to provide details of his contact with a US businesswoman and explain how any potential conflict of interest was addressed.

The assembly’s oversight committee gave Johnson 14 days to explain how grants and privileged access to trade trips were awarded to Jennifer Arcuri during his time as mayor. Johnson’s confidential response was sent to the watchdog on Tuesday night an hour after the initial deadline.

The letter was marked “confidential and not for publication” but a spokeswoman for the committee said: “It doesn’t answer any of our questions.”

The committee chair, Labour’s Len Duvall, has asked for legal advice about whether the watchdog can discuss the letter at an open meeting next Wednesday.

The meeting is also expected to decide whether the committee should use its powers to summon the former mayor to answer questions in person as it did over his failed garden bridge project.

And it could even decide to force Johnson to hand over private text messages and emails he sent to Arcuri. Duvall said the committee planned to take the matter further.

“Nothing in [Johnson’s] response, in our opinion, reflects the need for confidentiality,” he said. “In fact, the response is insufficient as far as our request for information is concerned.

“We are focused on our investigation and considering next steps. A number of options are open to us. They include speaking to various people and using our power of summons.”

The committee was alarmed by revelations in the Sunday Times that Arcuri was awarded thousands of pounds in public money, including £11,500 by the mayor’s promotional agency London & Partners.

Johnson’s office also intervened to give her a place on trade missions to New York and Tel Aviv with the then mayor, after she was initially turned down because she failed to meet the criteria.

This week, Arcuri confirmed she shared a “very close bond” with Johnson and he visited her east London flat up to 10 times, but she insisted she was not given favourable treatment by the then mayor or his officials.

Last month, Duvall wrote to Johnson asking for details and a timeline of all contact with Arcuri throughout his mayoralty.

He also asked for an explanation of how his “alleged relationship was disclosed and taken into account in any and all dealings with the GLA [Greater London Authority] and other parts of the GLA family”.

It is understood Johnson’s confidential response failed to provide those details. The prime minister has insisted “full propriety” was followed and he has no interest to declare over Arcuri.

Meanwhile, the Independent Office for Police Conduct is expected to make a decision before the end of the month on whether to launch an investigation into allegations of misconduct in public office.

An official at the Greater London authority formally referred the allegations to the police watchdog, because Johnson headed the mayor’s office for policing and crime as part of his role.

Separately, the current London mayor, Sadiq Khan, has launched an independent review of how Arcuri was given sponsorship and access to trade trips.

And the Department for Digital, Culture, Media and Sport is withholding more than half of a £100,000 grant awarded this year to Arcuri’s company Hacker House, pending a review into how the money was allocated.