The Warsaw Metropolitan Police said on Sunday that investigators are examining what they called an "eastern thread" – a possible connection to Russian actors.
Police described the attack as "large-scale" and said evidence points to actions "requiring appropriate planning and time coordination".
A 53-year-old man arrested on Friday on suspicion of sending false emergency alerts to police, claiming people at employees' addresses were in danger, has since been released.
Investigators established that his personal data and email account had been hijacked without his knowledge.
He is now treated as a victim, alongside two other individuals whose identities were similarly stolen to cover the perpetrators' tracks.
The incident came to light on 15 May, when police responded to an alert about a child in danger at the home of Tomasz Sakiewicz, the channel's editor-in-chief.
Officers entered the property and handcuffed his assistant, who was not complying with their instructions.
Sakiewicz went on air to denounce what he called a provocation.
The channel's programming director, Michał Rachoń, said the station was aware of around 30 similar incidents, all following the same pattern: false emails sent to police and other institutions claiming people at various addresses were suicide risks, had explosives or posed a threat to life.
The investigation is overseen by the Warsaw-Mokotów District Prosecutor's Office.
(ał)
Source: TVP Info