The Crown Prosecution Service’s special crime division is considering whether to charge MP Mike Amesbury after CCTV showed the politician punching a man in the street.
While the police are responsible for collecting evidence, the Crown Prosecution Service (CPS) is responsible for whether someone should be charged with a crime.
Cheshire Police has now handed the file to the CPS.
Mr Amesbury, MP for Runcorn and Helsby, voluntarily met with police following the incident in Frodsham, but has not been arrested.
Politics latest: ‘We’ve all got PTSD from Liz Truss’
Because of his position as a member of parliament, the case has been passed to the special crime division of the CPS in London, rather than the local department in the North West of England.
CCTV footage showed Mr Amesbury facing off for about 30 seconds with another man, before the MP hits the other person in the face.
Be the first to get Breaking News
Install the Sky News app for free
Read more from Sky News:
North Korea vows to back Russia until ‘victory’ over Ukraine
Public schoolboy who attacked sleeping students named
It is not clear what the pair were talking about – although Mr Amesbury claimed he was “threatened on the street following an evening out with friends”.
Elected as a Labour MP, Mr Amesbury has been suspended from the parliamentary party while an investigation takes place.
Cheshire Police said a 55-year-old man was voluntarily interviewed under caution and “released pending further enquiries”.
Keep up with all the latest news from the UK and around the world by following Sky News
The MP said in a statement he had contacted “Cheshire Police myself to report what happened during this incident”.
The incident happened in the early hours of Saturday in Main Street, Frodsham, near Cheshire.
In July last year, a 56-year-old man was convicted of stalking Mr Amesbury at his constituency office.
Please use Chrome browser for a more accessible video player
Prosecutors said he was seen staring through the glass and asked guards about their level of security.
The CPS confirmed it had received a file from Cheshire Police.
Cheshire Police, and the Labour Party have been approached for comment.