Mr Daniels said his current account does not even have an overdraft facility and wrote online that he has spent hours talking to his bank to try and resolve the situation.
He wrote on Facebook: "I woke up to my current account overdrawn by almost 1.2 million.
"I have been on the phone to Barclays for over 2 hours talking to various departments including the fraud department.
"I went to my local Barclays branch to take cash out my savings account to live on whilst my current account was suspended.
"I was then told in branch that I couldn't take cash out my savings account as Barclays has blocked all my accounts."
He said: "I have never had an overdraft option on my account I have only had the accounts since October 2016.
"In my current account there was £0.90 and in my savings there was £300 witch [sic] is my money to live on and for my bills."
A mini bank statement showed that four £250,000 sums were withdrawn from his account before £200,000 was then taken out which left him with a balance of -£1,199,999.10.
A Barclays spokesman said: "From the detail included in the mini statement, it is evident that the transactions could only have been made using login security information for the mobile banking app.
"We are carrying out a thorough investigation."
