TalkTalk customers are claiming to have been affected by the recent TalkTalk data hack before the date and time given by the firm.
While the telecoms provider gives the date of the morning of 21 October, several victims report being contacted on the telephone by scammers claiming to be from the firm prior to this.
Pensioner Judy Gunning, who was interviewed by the Mirror and the Telegraph, reported losing £15000 after a man contacted her, persuaded her that he was from TalkTalk and gained access to her computer. This took place on 10 September.
The Mirror also cited an unnamed victim who claimed to have been targeted last July.
One customer claimed to BBC Radio 5 Live to have received a "very convincing" call from someone who correctly cited his account number, and suggested that the firm might have been hacked several months ago.
It is unclear how many of these attacks were due to the hack.
These developments follow TalkTalk CEO Dido Harding receiving a ransom demand from a group claiming responsibility for the cyber-attack against the company.
The Metropolitan Police Cyber Crime Unit launched a criminal investigation on the breach, which has potentially resulted in the theft of personal data, including bank and credit card details, from 4 million customers.
A TalkTalk spokeswoman said: "We can confirm we were contacted by someone claiming to be responsible and seeking payment."
TalkTalk said the cyber attack was on its website and not its core systems. It said that customers could not directly have money stolen from the attack.
The company said hackers have not accessed TalkTalk My Account passwords.
Dido Harding has asserted that she will remain as TalkTalk CEO amidst continuing controversy over the hack. She has also defended the company’s cybersecurity policies and played down concerns about the company’s financial exposure in the hack.
