Nikola Filchev, Bulgaria's controversial and erratic former senior prosecutor, has masterminded the mysterious murders of a lawyer and a prosecutor back in 2000 and 2003, the interior minister has said.

"One of the versions is that former Chief Prosecutor Nikola Filchev and Aleksei Petrov, former agent of the State National Security Agency DANS, came together to eliminate Prosecutor Nikolay Kolev and lawyer Nadezhda Georgieva," Interior Minister Tsvetan Tsvetanov told the morning broadcast of TV 7 on Tuesday.

Georgieva was killed in her home in Sofia suffering nine blows from a kitchen cleaver on February 28, 2000. Witnesses claim the lawyer was handed USD 150 000 to give to Filchev as a bribe to make him stop an investigation against the state-owned deep-sea fishing company. Georgieva, however, did not give Filchev the cash and in a moment of a cyclophrenic crisis he killed her, plunging a kitchen cleaver in her head.

Kolev was a high-ranking prosecutor; he served as Deputy Chief Public Prosecutor of Bulgaria between 1994 and 1997. In January 2001, upon an application by the Chief Public Prosecutor, he was dismissed from his position as a prosecutor at the Supreme Cassation Prosecution Office with an order sending him into retirement.

Following his appeal submitting that he had neither reached the requisite age nor had asked for retirement, the courts decided in his favour. He resumed work as a prosecutor, this time at the Supreme Administrative Prosecution Office.

Kolev publicly stated his opinion that the Chief Public Prosecutor suffered from a psychiatric disorder, committed unlawful acts and ordered criminal proceedings on fabricated charges against persons he found inconvenient. Kolev alleged that, as a retribution for his disagreements with the Chief Public Prosecutor, he himself had been retired compulsorily.

Within a short period of time after Kolev's public accusations, several sets of criminal proceedings were brought against him and members of his family, on various unrelated charges. In the first half of 2001, Kolev wrote to the authorities and the press stating that he expected he would be arrested on charges of illegal possession of drugs which would be planted on him in an attempt to silence him.

Kolev repeatedly voiced in public his fears that he might be killed as part of a merciless campaign against him orchestrated by the Chief Public Prosecutor. On the evening of 28 December 2002 he was shot dead in front of his home. An investigation was opened on the same day and a number of investigative steps were carried out in the days and weeks that followed, including expertises and witness questioning.

Although a number of new investigative acts were ordered and carried out, the investigation was suspended repeatedly for failure to identify the perpetrator.