Perugia's Saadi Gaddafi has been suspended from the Italian football league following a failed drugs test.
Gaddafi signed for Perugia in June
Gaddafi, the son of Libyan leader Colonel Muammar, has been suspended indefinitely from Serie A but faces a permanent ban of up to two years should a second optional test prove positive.
On Tuesday,the Italian Olympic Committee revealed that Gaddafi was found to have an excessive amount of the performance-enhancing steroid nandrolone in his system following a test carried out after Perugia's match against Reggina on 5 October.
Gaddafi, who is suspended from Italian football activities until a final determination has been made on his case, is expected to demand a test on his second sample within the stipulated 10-day period.
The 28-year-old, who signed for the Italian club in June, had yet to play a first-team game for Perugia prior to the results.
"I was surprised when I heard the news," Gaddafi told al-Jazeera from the Perugia hotel where he lives.
"There will be a comprehensive investigation of the past few months when I visited several doctors in Italy, Germany and in Libya to discover which doctor gave me this substance that appeared in the test."
Perugia president Luciano Gaucci immediately jumped to the defence of his summer signing.
Speaking on an Italian website Gaucci said: "He takes medicines in order to heal a back problem, that's why he has tested positive."
Perugia captain Giovanni Tedesco said he was sure his team-mate had done nothing wrong and refused to rule out a boycott of Serie A.
"We are stunned about what has happened, we are convinced that he has never taken any prohibited substance and we are sticking by him," said Tedesco.
"He may have played little since he has been here, but he is an important member of the group.
"We have already discussed the problem and it was suggested that we stop playing for one or two weeks to think things over and fully understand the problems we are faced with."
Gaddafi is the latest Serie A player to test positive for a banned substance in recent months.
Last month, Inter Milan striker Mohammed Kallon tested positive for nandrolone, while Parma's Manuele Blasi was found with norandrosterone in his system.