Police found three cannabis farms in Hertfordshire Justin Sullivan/Getty Images

One of the top cage fighters in Britain has been jailed for a year for running a series of cannabis farms with his in-laws. Karel "Karlos" Vemola, a title-holding mixed martial artist originally from the Czech Republic, was convicted alongside his former partner Sarah Sharp and her elderly parents at St Albans crown court.

The 30-year-old had convinced Linda Sharp, 70, and her partner Terrance Byman, 72, to invest in a business running at least three cannabis farms in Potters Bar and Bushey in Hertfordshire, the court heard. They had seen the venture as "an ideal way to top up their pensions".

Vemola, whose nickname in the ring is "the Terminator", had started using the drug to help with the pain he sustained from his fighting injuries, the court was told.

Police caught wind of the scheme in January 2014, after they found evidence of farming following a burglary at one of the properties.

Peter Shaw, for the prosecution, said that police had found skunk cannabis worth £18,200, as well as UV lighting, ducting and plastic sheeting during raids on the three properties. Vermola had made around £6,500 from the enterprise by the time it was found, while the court heard he might have made up to £120,000 a year in his fighting career.

All four pleaded guilty to conspiring to produce cannabis.

Terrance Byman and Linda Sharp were both jailed for nine months, suspended for two years, while Sarah Sharp was given a one-year conditional discharge.

Vermola is the current champion of the Ultimate Challenge MMA light heavyweight category. He originally moved to London to pursue a career as a competitive bodybuilder, but had trained as a Greco-Roman wrestler in the Czech Republic.

He was discovered as a fighter while working as a bouncer in Tottenham, after he ejected two MMA fighters from a nightclub. He would go on to spend three years in the UFC, widely seen as the most prestigious MMA organisation in the world.