The Metropolitan Police has confirmed both they and the London Ambulance Service were called to "a report of an unwell woman" in the early hours of Sunday morning.
According to reports, the Chelsea winger had a row with the unnamed woman - who was taken to hospital - at his home in west London, and he remains in custody.
Mirror Sport added that his club have declined to comment on the alleged incident.
The 19-year-old star had previously tested positive for COVID-19 back in March, but explained at the time he had made a quick recovery.
He said on social media: "Guys, as you may be aware, I've had the virus for the last couple of days which I've recovered from.
"I've followed the guidelines and will be self-isolating for a week.
"I hope to see everybody soon, and hopefully we can get back on the pitch soon. Take care."
The news comes after a number of Premier League footballers have already been caught breaching the lockdown rules.
Aston Villa skipper Jack Grealish was fined by the club for having a party at his friend's flat, before allegedly crashing into parked cars and a set of iron railings.
Meanwhile, Manchester City defended Kyle Walker is facing disciplinary action after allegedly inviting a friend and two prostitutes to his Cheshire flat.
He later said: "I understand that my position as a professional footballer brings the responsibility of being a role model.
"As such, I want to apologise to my family, friends, football club, supporters and the public for letting them down."