A four-month investigation into the death of Costas Tsalikidis, a Vodafone software engineer who may have been linked to the recent phone-tapping scandal, is almost complete after the testimony of the mobile phone company’s CEO Giorgos Koronias yesterday.

Prosecutor Yiannis Diotis is conducting the preliminary probe into the death of the engineer, who allegedly hanged himself on March 9 last year — two days after spy software was discovered in Vodafone’s system.

Koronias refused to comment publicly after his two-hour testimony but sources said that he is likely to be the last witness questioned by Diotis. The prosecutor is now set to start compiling his report.

The police recently gave him a report with details about Tsalikidis’s telephone conversations and what they found on the technician’s computer hard disk.