A simple screw cap could help spare a man from jail, according to his lawyer - who has turned to Twitter to identify where it came from.

Patrice Reviron, a lawyer in Aix-en-Provence, believes that identifying where the red cap came from could help clear his client.

The 4.2cm diameter, 1.48cm high stopper was recovered in 2010, and sealed as evidence.

"It was not possible to determine where this stopper came from and what it was used for. This is an essential question for me. It can help to exonerate him or even completely remove him from the file," Mr Reviron said in an interview with Le Parisian.

His unusual public appeal has been retweeted more than 7,500 times, and prompted more than 1,000 replies - some serious, others less so.

But the lawyer has kept other details of the case quiet in a bid to avoid compromising the case, which has been referred to trial.

"I only want to know what this stopper was used for before it was found in the file. This is a criminal case, whose investigation has just been completed."