Broadcaster Danny Baker is being investigated by police over a "stupid" royal baby tweet that saw him sacked from his role presenting a weekly show on BBC Radio 5 Live.
The tweet, a photo showing a well-dressed man and woman holding hands with a suited chimpanzee with the caption "royal baby leaves hospital", was perceived by many as racist.
It is now being "reviewed and assessed by specialist officers".
A Metropolitan Police statement read: "An allegation has been received by the Metropolitan Police Service on Thursday May 9 in relation to a tweet published on the May 8."
"As is routine, the allegation will be reviewed and assessed by specialist officers."
Following his sacking, Mr Baker said he knew a royal baby was being born but claimed "he had no idea" it was the son of Meghan Markle and Prince Harry.
Baker told reporters: "It was up there only about eight minutes or something, until somebody I follow said Dan you know...she's mixed race.
"And I took it down, and that's it, as I said Occam's Razor [the most simple explanation is usually correct], that's it."
The tweet has since been deleted and Baker apologised in a series of posts, but a BBC spokesman said the tweet "goes against the values we as a station aim to embody" and was "a serious error of judgement."
The spokesman added: "Danny's a brilliant broadcaster but will no longer be presenting a weekly show with us."
Baker, 61, who presents a weekend show on BBC Radio 5 Live, apologised again on Wednesday evening, saying the joke was intended to poke fun at the Royal family.
He said in a follow-up tweet: "Would have used same stupid pic for any other Royal birth or Boris Johnson kid or even one of my own. It's a funny image. (Though not of course in that context.) Enormous mistake, for sure. Grotesque.
"Anyway, here's to ya Archie, Sorry mate."