Unmesh Desai is the City Hall representative for City and East, which incorporates Newham, Tower Hamlets, the City of London and Barking and Dagenham.
This paper understands he has been administratively suspended, but Labour said it was unable to comment on why.
A City Hall spokesperson said: “AM Desai remains the assembly member for the City & East constituency.
“He is no longer part of the Labour Group within the assembly but will operate as an independent member.
“The assembly will consider in due course whether any changes are required to existing committee membership, in line with statutory proportionality requirements.”
Mr Desai did not respond to requests for comment.
