Releasing the latest in a series of wiretapped tapes on Tuesday, opposition Social Democrats leader Zoran Zaev said the conversations in the new batch of recordings prove the authorities tried to cover up the killing of 21-year-old Martin Neskovski.

Neskovski was beaten to death the night that the ruling VMRO DPMNE celebrated its election victory on June 6, 2011.

Eyewitnesses claimed that a policeman in uniform killed him, sparking protest rallies against alleged police brutality.

For nearly two days, the police denied the incident had happened but then changed their story, confirming the victim’s identity and claiming they had the murder suspect in custody – Igor Spasov, a member of a special police unit called the Tigers.

Officials insisted that Spasov was not on duty at the time and so they were not responsible for the murder.

But the wiretapped conversations released on Tuesday allegedly reveal that the Prime minister’s chief of security, Dejan Mitrevski Urko, called in Spasov that night, meaning that the authorities were responsible for his actions.

The opposition said that the tapes involving interior minister Gordana Jankulovska, her spokesman Ivo Kotevski, the PM’s chief of staff Martin Protugjer, secret police chief Saso Mijalkov and premier Nikola Gruevski, showed that there was a plot to pin the murder on the policemen alone and avoid responsibility falling on higher officials.

The tapes allegedly show that Mitrevski even kept the interior minister in the dark for two days about what happened.

In another conversation, secret police chief Mijalkov calls minister Jankulovska to tell her the case has been closed and that Spasov has turned himself in, only to receive later a call from her spokesman Kotevski who is worried that Spasov will not admit to the murder, which could expose the ministry’s role in the affair.

According to the conversations, the interior minister learns what happened only after the case piled public pressure on the authorities. She was initially told that Neskovski was a drug addict who died of an overdose before evidence surfaces that he was beaten to death.

“They waited two days to tell me what happened. I told him, you should have told me right away we could have done something, call an ambulance, we would have thought of something to get him out of this,” Jankulovska says.

Jankulovska then complains to the PM’s chief of staff that “one cannot hide a murder” and that the PM’s chief of security Mitrevski is out of control.

She also discussed with her spokesman how to handle damage control in the press and what information to give to pro-government media.

Police spokesman Kotevski suggests “maybe we should feed them information that he was a VMRO [ruling party] member who was killed by an [opposition] SDSM policeman”. At the time, pro-government TV station Sitel did speculate about such a scenario.

Jankulovska appears worried about Mitrevski and what she refers to as a “parallel police system”. In several conversations she complains about the possible implications of the murder case on the ruling party’s image.

“That boy neither ran nor resisted them… He tripped and this guy beat the hell out of him,” Jankulovska is heard saying.

Prime Minister Gruevski in 2011 said that the authorities reacted swiftly in the case and that Spasov was not on duty at the time. He then blamed the media and opposition for politicising the case to undermine his government.

The new tapes also include a conversation between Gruevski and the interior minister in which he appears to instruct her to come out in public and say Spasov acted on his own and was not on duty at the time.

Spasov was sentenced to 14 years in prison in 2012. The same year, the father of Martin Neskovski committed suicide.

The killing of Neskovski triggered protests against police brutality that lasted for months. After the tapes were revealed on Tuesday, calls for new protests emerged on social networks.

The opposition Social Democrats started releasing wiretapped tapes in February, accusing Gruevski and his cousin, secret police chief Mijalkov, of orchestrating the illegal surveillance of over 20,000 people over several years, including journalists, judges, prosecutors, mayors and even government ministers.

As the political crisis in the country escalated, the Social Democrats announced they would launch mass demonstrations later this month aimed at ousting Gruevski’s government.

Jankulovska held a press conference to repeat the government line that the tapes were cut, edited and created by unnamed “foreign secret services” in collaboration with the opposition in order to destabilise the country.