Jack Fincham has been arrested on suspicion of drug-driving and having false plates on his car.
The 31-year-old reality star - who shot to fame in 2018 when he won 'Love Island' alongside then-girlfriend Dani Dyer - was stopped in Swanley, Kent, on August 26th and gave a blood test.
According to The Sun newspaper, he was also held on suspicion of careless driving and driving without insurance.
Jack was released under investigation until November 26th.
He has not been charged with drug-driving and denies drug consumption.
Jack's solicitor Conor Johnstone, of M.A.J Law, said: "Mr Fincham has not been charged with drug driving and denies any drug consumption whatsoever.
"There is no evidence at this stage that Mr Fincham drove whilst over the legal limit and we are hopeful that his blood results will prove the same."
A source also told the publication he was using private plates, rather than false plates.
In May, father-of-one Jack told how he manifested his 'Love Island' victory.
During the series, he kept a note in his wallet that read: "I Jack Fincham am going to win Love Island 2018."
Speaking from Robert Hisee’s Holistic Retreat in Marbella, the star said: “I had the note in my wallet so it was with me every day.
"I used to say to myself day in day out when I went into 'Love Island' I knew I was going to win it but after the win, I never had another goal to move onto to raise my standards."
But now, Jack's new dream is to become “one of the biggest actors in the UK" following his cinematic debut in the crime flick ‘The Last Heist’ in 2022.
He said: “One of my goals is to become an actor, so a new affirmation of mine is saying, ‘I am one of the biggest actors in the UK.' "