BUCHAREST, Romania (AP) — A court ruling that Romanian prosecutors obtained evidence illegally could collapse murder and child pornography trials in the country, a top legal expert said Friday.

Romania's Constitutional Court ruled this week that secret protocols signed between the Prosecutor's office and the Romanian Intelligence Service in 2009 and 2016 were unconstitutional. The system helped prosecutors obtain evidence through phone taps and other electronic surveillance. Prosecutors declassified the protocols last year.

Augustin Zegrean, chief judge of the Constitutional Court from 2010 to 2016, said that "bribery, drug trafficking, people trafficking, murder, child pornography and other cases" could be affected by Wednesday's ruling.

"What about people currently serving sentences? Do you let them out? " Zegrean told The Associated Press by telephone.

The ruling is a victory for Romania's government, which almost daily denounces the secret protocols. Government officials have compared the surveillance of graft suspects that resulted from the agreements to the activities of Romania's Securitate communist-era secret police.

Critics claim the government is trying to protect corrupt officials and thwart the anti-corruption fight.

Prosecutors say the country's domestic intelligence agency has provided expertise and support in complex murder cases or money laundering probes. Anti-corruption prosecutors have argued they cooperated with the intelligence service because they lacked the expertise and funds to carry out complex surveillance operations themselves.

The court is expected to explain its decision in the next month.