Last minutes of emission after the invasion
A group of several hundred staff have continued to work at the station, broadcasting online, since it was officially shut in June
Greek riot police have cleared the headquarters of the former state broadcaster ERT, using tear gas to gain entry and arresting several people.
Police formed a cordon round the building in Athens, before going from room to room to evacuate protesters.
Former employees have occupied the building since the government closed ERT and sacked its 2,600 staff in June.
Greece’s conservative-led coalition said the state broadcaster cost too much to run in an economic crisis.
The closure of ERT prompted a left-wing party to withdraw from the governing coalition of prime minister Antonis Samaras in protest – a move which almost brought down the government.
The BBC’s Mark Lowen, in Athens, says the question is whether the ERT debacle again fuels social unrest here – and how much stomach the Greeks still have for a fight.
Following the announcement of ERT’s closure in June, hundreds of staff refused to leave the building and continued to broadcast their programming via the internet.
But early on Thursday, Greek police arrived to secure the building in Agia Paraskevi, a suburb in the north of Athens.
Riot police used tear gas to disperse about 200 protesters outside the building, and then cleared each room inside.
A member of staff inside the building told the BBC that once officers entered, it was fairly peaceful.
Twenty or so workers were led out but three refused to go and were arrested. Police have now surrounded the building and protesters are gathering.
The state-run Athens News Agency reported that Panagiotis Kalfagiannis, a journalist and head of the ERT employees’ union, Pospert, was one of those held for public order offences.
ERT was Greece’s only TV broadcaster until the advent of private TV channels in 1989.
Despite several major overhauls to keep up with fierce private competition, a fall in ERT’s ratings in the mid-1990s triggered a long-running debate about its cost and efficiency.
In June, as Greece attempted to satisfy international creditors that it was fulfilling its debt restructuring and bailout commitments, the prime minister, Antonis Samaras, announced the closure of ERT.
He said the Greek exchequer could no longer afford to pay for a public broadcaster that cost 300 million euros ($406m; £252m) anually, and has refused to reinstate ERT unless it accepts a complete restructuring.
An interim TV station, called Public TV or DT, has been broadcasting in Greece since July while a restructured public broadcaster, called Nerit, is not expected to begin operating before 2014