Verizon is pushing for a $1 billion discount on its $4.83 billion deal to acquire Yahoo’s core assets, following recent news of network hacking and spying allegations at the internet company.

Last month, Yahoo confirmed its network was subject to a breach in 2014, which it put down to a “state-sponsored actor” stealing information from more than 500 million accounts.

The company was again in the spotlight this week, after it was alleged it had scanned hundreds of millions of user emails, after a request from a US intelligence agency.

According to the New York Post, there are now concerns at Verizon that the recent bout of bad headlines has wiped some of Yahoo’s value.

Tim Armstrong, CEO of Verizon-owned AOL, has become upset about the lack of disclosure about the hack, and is even considering whether the US operator should pull out of the deal, said a source.

Armstrong reportedly met with Yahoo executives pushing for a price reduction, but Yahoo’s team is also standing firm, said The Post.

The internet company is claiming that there is no legal recourse to change the terms, and discussions are ongoing.

Verizon said it only learnt about Yahoo’s network breach two days before it became public, when the company revealed certain user account information was stolen from its network, which may have included names, email addresses, phone numbers, date of births, hashed passwords and, in some cases, encrypted and unencrypted security questions.

At the time, Verizon said it would evaluate the investigation. Notably, in an SEC filing on 9 September, relating to the Verizon sale, Yahoo said it did not have any knowledge of any incidents or security breaches of its systems.

The acquisition is thought to be going through final regulatory clearance.