Latonya Skye-Patterson didn't know a children's trust fund had been set up for her until her college tutor suggested she check online.

"I found £955 in it, which was a lot. Much more than I expected... and it helped me a lot," she said.

New figures show 728,000 people aged 18 or over have £1.4bn available to claim, but many are unaware the accounts exist, according to a charity that tracks money losses.

Now a senior MP has backed calls for automatic payments to some of these accounts - a scheme the government says would be complex and expensive.

Latonya, 20, is one of 6.3 million people born between September 2002 and January 2011 who have a children's trust fund started by a government payment - usually £250.

The idea is that the value of a long-term tax-free piggy bank will appreciate by their 18th birthday.

The average size of a children's trust fund is estimated to be around £2,000, due to growth over the years and additional contributions from family and friends.

But like hundreds of thousands of others, when Latonya was 18, she had no idea her fund existed.

Sharing FoundationA charity that helps people track down lost and unclaimed money is calling for some of these funds to be automatically paid out if account holders have not claimed them by the time they turn 21.

“Honestly, I think it’s a great program,” Latonia said. “My college tutor told me about it, but my brother, who is a year older than me and went to the same college, wasn’t told about it, so it was down to luck who knew and who told who.

"Especially with the cost of living, having it automatically when you don't know you have it can really give people the break they need."

This "21-year-old default withdrawal" plan covers accounts where a parent or caregiver took no action to establish a trust after receiving an initial certificate from the government.

These "lost" funds are known as "HMRC allocated accounts" and there are 449,000 accounts holding £927 million.

Campaigners are calling for the funds to be automatically paid to account holders using their National Insurance numbers if they are not claimed by the time they turn 21.

National Insurance numbers can be used to trace account holders through PAYE payslips, student loans or benefits.

Sir Geoffrey Clifton-Brown is a Member of Parliament and Chairman of the Parliamentary Public Accounts Committee.

He told Radio 4's Money Box as an MP that he supported the idea of ​​automatic payments.

"I liken this money to a treasure trove buried in the vast expanse of sand on a (desert) island and expect these poor beneficiaries of the Children's Trust Fund to find it," he said.

"I think we can do more to encourage governments to find recipients."

Sir Geoffrey said he would put pressure on the Treasury and HMRC the next time they appear before the Public Accounts Committee on the issue.

HM Revenue and Customs said it was grateful for the suggestion from The Share Foundation of a "21-day default withdrawal" scheme, but said the proposal was complex and not easy to implement.

A spokesman said: "It will require careful legal consideration for HMRC to close these accounts, access the deposits in these accounts and transfer them with or without the consent of the owners."

They added that the move would also require "operational systems and resources" between government departments and children's trust fund providers to monitor transactions.

"The government is committed to reintroducing CTFs to all young people and recognizes the importance of ensuring young people can benefit from these funds when they reach adulthood."