By Helen Fawkes
BBC News, Kiev
Hundreds of Ukrainians are expected to form a candlelit chain on Sunday to mark the anniversary of the murder of a prominent opposition journalist.
Mr Gongadze had been campaigning against government corruption
Georgiy Gongadze was abducted in Kiev seven years ago. His headless body was later found buried in a forest.
The death triggered a major political scandal and became Ukraine's most high-profile murder case.
President Viktor Yushchenko said finding the killers was a top priority - but no-one has been convicted.
Mr Gongadze was an outspoken critic of the Ukrainian authorities at a time when there was little freedom of speech.
The president at the time, Leonid Kuchma, was said to be implicated in the case by secret tape recordings. He has always denied involvement.
The case sparked mass protests that culminated in the Orange Revolution, leading to the election of Mr Yushchenko.
He pledged to solve the case, but it has proved to be extremely difficult.
A former interior minister who was considered to be a key witness was found dead hours before he was due to testify.
The prosecutor's office said he had committed suicide by shooting himself twice in the head.
Three former policemen have been charged with carrying out the killing of Mr Gongadze but their trial has been suspended indefinitely.
No-one has ever been charged with ordering the murder.
The seventh anniversary of Mr Gongadze's abduction and murder comes as Ukraine prepares for an early parliamentary election at the end of the month.
Many people are disappointed that the president has failed to bring the killers to justice.