Cameroon and Lazio 17-year-old player Joseph Minala in age row

Lazio were forced to release official documents and threaten legal action to prove a youth team player was still a teenager and not in his 40s.

Joseph Marie Minala, 17, came in for abuse on social networking sites after releasing a picture showing him looking much older than his teenage years. Quotes also appeared in Senegalese media that said Minala was 41.

The Italian club and Minala's agent rubbished claims that he was a cheat, producing the paper work to prove he was the correct age.

In an attempt to bring an end to the allegations, Lazio announced on the club's official website that they "confirm the absolute legitimacy of the paperwork filed with the federation and denounce the latest attempts, from hostile domains, to cast a sinister light over the club's operations.

"From now on, [the club] announces that it will take any action aimed at ending such behaviour out of respect for the fans and the player while reserving the right to take action against anybody responsible [for such behaviour] to defend the good name of the club and the footballer."

Earlier on Wednesday, the player's agent, Diego Tavano, told La Gazzetta dello Sport: "If you talk to him, then you realise from the way he speaks that he's still absolutely a 17-year-old lad. Joseph had a difficult childhood, that's the issue."

Minala arrived in Italy three years ago and was spotted by Lazio's talent scouts when he won the Trofeo delle Regioni 2013 as part of a representative of the state of Lazio.

He was playing for Vigor Perconti at the time and their owner Maurizio Perconti said: "I cannot deny that he looks older than he is, but his paperwork is all genuine."