Manchester police said they had arrested a man on suspicion of rape and assault on Sunday after Manchester United suspended England forward Mason Greenwood following allegations on social media.
"Greater Manchester Police was made aware earlier today (Sunday 30 January) of online social media images and videos posted by a woman reporting incidents of physical violence," said a statement.
"An investigation was launched and following enquiries we can confirm a man in his 20s has since been arrested on suspicion of rape and assault.
"He remains in custody for questioning.
"Enquiries are ongoing."
Under English law, alleged and actual victims of sexual offences cannot be named.
Images and allegations were reportedly visible on a woman's Instagram on Sunday morning and were subsequently widely shared across other forms of social media.
They have, however, since been deleted.
In the afternoon, United announced that Greenwood, 20, had been suspended from training or playing with the Premier League giants.
"Mason Greenwood will not return to training or play matches until further notice," said a club statement.
In an earlier statement, United had said they were aware of the allegations and images on social media, adding: "Manchester United does not condone violence of any kind."
Greenwood, a product of United's academy, has yet to make any public comment.
In September 2020 both Greenwood and Manchester City midfielder Phil Foden were sent home from an England squad in Iceland after a breach of the team's coronavirus guidelines following their senior international debuts.
That meant they did not travel to Denmark for a Nations League match, with Greenwood yet to earn a second England cap.
Allegations emerged in the Icelandic media that Foden and Greenwood were visited by two local girls during the trip but England manager Gareth Southgate said at the time: "Nobody from outside our party has been into the areas of the hotel that we occupy."
Sunday's statement regarding the arrest of a man on suspicion of rape and assault comes just under a fortnight since Manchester United great Ryan Giggs's trial on charges of assaulting his ex-girlfriend and her sister was delayed until August because of a backlog in the courts.
Giggs, 47 has been on leave from his role as Wales manager since November 2020 when he was arrested.
The Old Trafford hero is accused of controlling and coercive behaviour against his former girlfriend Kate Greville between August 2017 and November 2020.
He has also been accused of assaulting Greville and common assault of her younger sister, Emma Greville, at his home in the Manchester area, on November 1, 2020.
Giggs has denied the allegations and pleaded not guilty to all charges.