AN OFF-DUTY police officer has earned the nickname "Rambo" after he jumped into freezing cold water to free a teenager who was trapped in his car after it rolled into a ditch. 

PCSO Matt Grimwood, who is based at Brentwood, was on his way to work when he was flagged down by a concerned motorist in Hammonds Road, Chelmsford. 

A combination of mud and icy conditions had caused the driver, 18-year-old Sam Hooper, to lose control of the car whilst he was travelling to college.

Without warning, the black Ford Fiesta Zetec ploughed up a grass verge and into a ditch where it landed on its roof.

Seeing the overturned car, Matt leapt into action and waded through knee-deep water to reach the vehicle. He shouted for Sam to pass his keys through the window and worked to free him from the boot.

“I done what any other officer would have in similar circumstances” said Matt, “I’m pleased that I was there to help and that the incident wasn’t more serious.”

Sam was miraculously unharmed after the crash at 8.15am on Monday, February 29.

Sam's Mum, Julie James, has thanked PSCO Grimwood and praised his actions: “We are really grateful for Matt's help, he’s a proper hero. Sam was shaken-up and bruised, but thankfully he's on the mend now.

"He's been telling all his friends at college that ‘some Rambo guy’ came to his rescue!”