Melbourne defender Joel Smith has been hit with a ban of four years and three months by the AFL after breaching five anti-doping rules.

The ban means Smith is prohibited from playing at any level of Australian Football, or any other sport that signs up to the World Anti-Doping Agency (WADA) code, until early 2028.

The 28-year-old's ban has been agreed to by WADA, Sport Integrity Australia (SIA) and the AFL.

Smith tested positive for cocaine during a routine drug test on game day in August 2023.

It later emerged he had sent text messages to teammates saying he had obtained the drug and offered it to them, which under anti-doping laws is considered trafficking.

Under those laws, he was found guilty of trafficking and/or attempting to traffic cocaine.

Three of the five rule breaches relate to trafficking or attempting to traffic cocaine.

"The outcome in this matter, in which Joel Smith has been suspended for more than four years, reflects the seriousness with which the AFL treats breaches of the Australian Football Anti-Doping Code and is a salutary lesson for any player using illicit substances that are prohibited under the WADA Code," AFL boss Andrew Dillon said in a statement.

"The use of performance-enhancing substances is strictly prohibited in Australian Football and the AFL will continue to work with Sport Integrity Australia to identify and prosecute the use of such substances in competition and other conduct prohibited by the Australian Football Anti-Doping Code.

"The AFL does not in any way condone the use of illicit drugs.

"If a player chooses to use illicit drugs, the potential consequences are substantial, including risks to health and safety and of losing the privilege of playing professional football, as has occurred here."

Under the terms of the suspension, Smith is prohibited from participating in any sports that have adopted a World Anti-Doping Code-compliant anti-doping policy until January 9, 2028, although he may return to training from November 2027.