French attacker Samir Nasri has had his doping ban increased from six to 18 months, a statement from UEFA has confirmed.
Nasri was given a six-month ban by UEFA in February after receiving an intravenous treatment which was in breach of the World Anti-Doping Agency's rules.
UEFA's ethics and disciplinary inspector had argued that the ban was insufficient, and the suspension has now been extended from six months to 18 months.
"The UEFA Control, Ethics and Disciplinary Body's decision of 22 February 2018 is amended as follows: 1. The player Samir Nasri is suspended for eighteen (18) months. This suspension will start running on 1 July 2017," read a statement from UEFA.
"2. The player Samir Nasri is allowed to return to training, with any football club starting from 1 November 2018."
Nasri started his professional career with Marseille, and also represented Arsenal, Manchester City and Sevilla before a short spell at Turkish outfit Antalyaspor.
The 31-year-old, who represented France on 41 occasions between 2007 and 2013, is currently a free agent.