Leslie Grantham "remains poorly and is being taken care of by medical staff", a representative for the ex-EastEnders actor has told the BBC.
The confirmation follows a story in The Sun saying the 71-year-old was "gravely ill" and "fighting for his life".
The newspaper reported that Grantham - who played "Dirty" Den Watts in the BBC soap - had returned to the UK from Bulgaria to receive medical attention.
His agent said a statement would be issued "at the appropriate time".
Grantham moved to Bulgaria after filming TV series The English Neighbour there in 2010.
The actor appeared in EastEnders from 1985 to 1989, when his character was seemingly murdered.
Dirty Den subsequently returned to Albert Square in 2003, only to be definitively killed off in 2005.
Grantham was written out of the soap after photos emerged of him apparently exposing himself in his dressing room.
The actor subsequently revealed he had tried to kill himself three times as a result of the scandal.