Odin Tunningley admitted possessing a lock-knife at Porchfield Business Park on May 28.
Tunningley, 40, arrived at the business park as police were conducting a search warrant for drugs and drug-related items.
“Police were also made aware of potential motorcycle gang warfare, which was predicted may have been coming to the Isle of Wight,” said Liz Miller, prosecuting, at the Isle of Wight Magistrates’ Court.
Island group The Lost Souls, the former Grim Riders, were embroiled in a feud with a mainland group called The Bandidos, the court heard.
While police were carrying out the drugs search, Tunningley arrived and was searched by officers — during which, officers found a small lock-knife inside his jacket pocket.
The dad-of-four, of School Green Road, Freshwater — a member of The Lost Souls — was arrested after he told officers the weapon had been given as a gift by friends.
“He explained he went to the site to sort out a tyre that was bald and wanted to get it replaced,” said Miss Miller.
For Tunningley, convicted of actual bodily harm in 2015, James Cameron said his client recalled getting the knife two weeks earlier and putting it in his pocket, which he forgot about.
Jobless Tunningley is an armed forces veteran who served in the Royal Artillery between 2001 and 2006, with tours of Northern Ireland and Iraq to his name.
“He has been diagnosed with post-traumatic stress disorder. He doesn’t blame that for this offence and realises he made a very foolish mistake, which he regrets,” said Mr Cameron.
“He says he has been affiliated to the Lost Souls for about a year and is not involved in any gang warfare or violence in any way.”
Magistrates told Tunningley they accepted his explanation for the knife and handed him three months’ curfew, fitted with an electronic tag, to remain indoors between 7pm and 7am daily.