“It has been brought to my attention that you maintained a friendship with Ms. Jennifer Arcuri, and as a result of that friendship allowed Ms. Arcuri to participate in trade missions and receive sponsorship monies in circumstances where she and her companies could not have expected otherwise to receive those benefits,” said the referral letter, attributed to the Greater London Authority’s monitoring officer, Emma Strain.

“This will take time to thoroughly assess and consider before any decision is taken as to whether it is necessary to investigate this matter,” the police watchdog said in a statement.

The ITV program, “Exposure,” will feature Ms. Arcuri in an episode titled “When Boris Met Jennifer.”

Ms. Arcuri said that she has tried in vain to get in touch with Mr. Johnson, seeking help to handle the media scrutiny. She told ITV that she had become “collateral damage” while the prime minister seemed to have escaped unscathed.

She said that when she called his personal number, she was passed to someone who spoke Chinese. Another time, she said, Mr. Johnson hung up the moment he heard her voice.

She told the broadcaster that she felt she had been “brushed off” as if she was “one of Kennedy’s girlfriends showing up to his White House switchboard.” (She apparently was referring to President John F. Kennedy.)

The show suggests, according to ITV News, that the pair had a four-year affair.

Ms. Arcuri did not directly admit to an affair with Mr. Johnson, according to the broadcaster, but said that “half the people” who reached out to her after the story about their relationship was revealed had advised her to “admit the affair, fall on the sword, get it over with.”