Martin Lewis says one million Brits have £2,000 that they know nothing about

They don't call Martin Lewis the Money-Saving Expert for nothing and he's only gone and done it again.

Watch his video here:

Lewis shared the revelation to Twitter yesterday (23 January) and captioned the video: "Age 12 to 20 (or the parent of someone who is): are you one of up to 1m people missing out on possibly £1,000 savings you don't know about?"

He then urged people to share the video with 'anyone affected', even if this huge amount - and potentially much-needed - cash is something you can't personally claim.

He began the video by explaining that this money comes in the form of a Child Trust Fund - a tax-free savings account that the government set up for those born between 1 September 2002 and 2 January 2011.

The accounts were set up with £250 from the government, but depending on a child's personal circumstances, they could have been given as much as £500.

This was done with the aim of providing 'a sum of money when a child reached adulthood'.

And the money in the funds can be accessed once the account holder turns 18.

Lewis said: "Of the 6.3 million Child Trust Funds that were active, it’s thought up to one million of them are lost.

"Meaning people have lost track of them or are unaware you have them - and that could be you."

Lewis then cited the latest figures from HM Revenue and Customs (HMRC), which estimate that these funds could contain an average of £2,100.

He added: "I think if it was inactive and nobody had put money in you've probably got less in that that, but it's still likely to be £300, £400, £500, £1,000 or possibly more."

Lewis then explained how people can find their Child Trust Funds.

Lewis also recommends comparing the account's interest rate to the top Junior ISA's, the 'successor' of the Fund after it was closed in 2011, and transfer the money to a Junior ISA account using their transfer form.

As you can imagine, people were naturally grateful for the head's up.

One Twitter user praised: "I've got two. We got them in 2007, I think, and invested them but no idea where they are so will have a look ! Cheers Martin!"

"Great advice. Thank you, Martin," added a second while a third wrote: "I did this last year for my daughter. She received over £1,700 !!! Completely forgot about the government savings but it had been invested well! [sic]"