Matty Johns' youngest son Cooper, 21, pulls an epic prank on his father live on radio... leaving the NRL legend gasping for air and 'about to faint'

Footy legend Matty Johns' youngest son Cooper has often been told he bears a striking resemblance to former Newcastle Knights captain, Kurt Gidley.

So on Friday, Cooper decided to pull an epic prank on his father live on-air during the Kyle and Jackie O show - leaving the NRL great gasping for air.

Like father, like son! Matty Johns' son Cooper pulled an epic prank on his football legend father Matty live on-air during the Kyle and Jackie O show (Matty and Cooper pictured) 

'You know we've had this chat before... but heaps of people keep messaging me... they think Kurt Gidley is my dad and it's just starting to rattle me a bit,' Cooper began.

Matty responded: 'I've told you at least a dozen times, if you take notice of imbeciles on social media then you're a wood duck yourself.'

But Cooper persisted, pointing out his lighter hair and blue eyes, which aren't features he shares with his famous father.

Could it be? After years of being told he resembled former Newcastle Knights captain Kurt Gidley, Cooper called his father to ask for a DNA test to prove they were biologically related (Pictured Kurt with his wife Brooke) 

'Oh, f**king hell, please! People say to me all the time how much we look alike,' Matty interrupted him.

'If you're really concerned about this you're probably better off having the discussion with your mother,' he said, referring to his wife Trish.

Cooper then drew his father's ire by asking him to publicly declare that he was 'really his son' on his radio show, The Matty Johns Podcast, to 'clear it up, once and for all'.

'I've told you at least a dozen times, if you take notice of imbeciles on social media then you're a wood duck yourself,' Matty told Cooper, adding he should ask his mother Trish (Matty pictured with Trish) 

'Can you imagine how that looks... People will think "I've never heard that rumour, that must be some truth in it",' Matty said, explaining how it would only make things worse.

Finally Cooper decided to play on his father's greatest fear - needles.

'When I get back can we just do a DNA test?' he asked.

Not going to happen:  Cooper then drew his father's ire by asking him to publicly declare that he was 'really his son' on his radio show, The Matty Johns Podcast, to 'clear it up, once and for all'

After stony silence, Matty responded between deep breaths: 'F**k mate, now you're rattling me.'

Thankfully for the former Footy Show host, radio host Kyle Sandilands jumped in to save him just before he started to hyperventilate.

'Only lying, sucked in,' Kyle gleefully chided his old friend.

Epic: Finally, Cooper decided to play on his father's greatest fear - needles. 'When I get back can we just do a DNA test?' he asked, leaving Matty gasping for air 

Matty then revealed he 'was about to faint' after Cooper suggested they get a needle to perform the DNA test.

Matty and Trish share two sons, Cooper, and his older brother Jack.

Both of the boys are following in their father's footsteps, with Cooper playing professional rugby for Melbourne Storm while Jack plays for the South Sydney Rabbitohs. 

Following in dad's footsteps: Matty and Trish share two sons, Cooper, and his older brother Jack. Both of the boys are following int heir father's footsteps, with Cooper playing professional rugby for Melbourne Storm while Jack plays for the South Sydney Rabbitohs (Matty, Cooper and Jack pictured)