Boris Johnson refused six times to answer questions over claims he failed to declare potential conflicts of interest over his close friendship with an American businesswoman.
The Prime Minister was given the opportunity to deny the claims, and to deny a relationship with American model-turned-tech entrepreneur Jennifer Arcuri.
But he refused to answer questions from journalists on the subject during his flight to New York to attend the United Nations General Assembly.
The PM also refused to say whether he would support a full inquiry into the claims, despite a allegation of misuse of public funds.
London’s City Hall and the Department for Culture, Media and Sport are both examining allegations made in the Sunday Times.
According to the report, Ms Arcuri gained access to three trade missions Mr Johnson led in 2014 and 2015, while Mayor of London.
The paper says Ms Arcuri was also, separately, given £126,000 in public funds in the form of three separate deals.
One of these, according to the paper, was from the organisation London & Partners for which Johnson was responsible as London Mayor - handing her firm £10,000 sponsorship money for an event in 2013.
In a statement to the Sunday Times, Ms Arcuri did not address her friendship with Mr Johnson.
She said: “Any grants received by my companies and any trade mission I joined were purely in respect of my role as a legitimate businesswoman.”
