By Richard Galpin
BBC News, Athens
The Greek prime minister's chief of staff has been cross-examined by a parliamentary committee probing a spy scandal that has gripped the nation.
The phone of PM Costas Karamanlis was among those tapped
Two months ago, the government revealed the phones of the prime minister and other high-ranking officials had been tapped for more than a year.
It started in 2004 - the year of the Athens Olympics. It is said to be Greece's worst modern spy scandal.
The committee has already questioned executives from Vodafone and Ericsson.
The prime minister's chief of staff, Yiannis Angelou, gave little away in three hours of testimony.
He said his role had only been to assess the seriousness of the situation and then to inform the prime minister immediately.
When asked who was behind the operation, he answered: "Justice will tell".
But he did confirm that Vodafone requested to meet him just hours after a senior Vodafone network manager was found hanged in his apartment in Athens.
As the parliamentary investigation proceeds, so too does the inquiry into the death of the Vodafone network manager, Costas Tsalikidis.
The official verdict was that he had committed suicide.
The lawyer representing his family has told the BBC he has now received three letters, one of them signed by someone currently in hiding, alleging that Mr Tsalikidis was murdered.
In February, it was revealed that highly sophisticated software had been secretly inserted into the Vodafone network, enabling the mobile phones of at least 100 people to be constantly monitored throughout the year of the Olympics.
As well as the prime minister's mobile phone, those of senior cabinet members and police and military officials had all been tapped.
Journalists and businessmen of Middle Eastern origin were also among the targets.
Many here, including politicians, are convinced it was the work of the United States' intelligence agency. The US is supposed to be a close ally of Greece.