OSLO Reuters) – Norwegian police said on Monday they were investigating allegations that some listening numbers at Tidal Music, owned by Jay-Z, Beyonce and other stars, were artificially inflated.

A complaint filed last year by groups working for Norwegian artists and record labels said the alleged fraud had deprived other artists of their fair share of subscription revenues.

Tidal, which began life as Norwegian start-up Wimp, has previously dismissed the allegations and its lawyer Fredrik Berg on Monday denied any wrongdoing.

“Tidal is not under suspicion in this case,” Berg, of the law firm Fend, said, adding the company was in a dialogue with police.

The probe follows an investigation by Norwegian business daily Dagens Naeringsliv (DN) last May that Tidal had manipulated user data, citing internal data from the company it said it had had access to.

“We’ve begun an investigation to confirm or reject the suspicion of manipulation,” said Oekokrim, the Norwegian National Authority for Investigation and Prosecution of Economic and Environmental Crime, in a statement on Monday.

The investigation looked at “whether someone has manipulated the number of times certain songs have been played,” Oekokrim added, but without naming any suspects.

DN asked a research group specialized in data security at the Norwegian University of Science and Technology (NTNU) to review the data.

In its report, dated April 10, 2018 and made public following DN’s publication of the story in May, the group found there had been a manipulation of the data at certain times.

Tidal last year denied any manipulation had taken place and said the DN article was factually wrong. The newspaper said it stood by its reporting.

Jay-Z, whose real name is Shawn Corey Carter, in 2015 bought the company behind the Wimp service for 464 million Swedish crowns ($51.90 million), and owns it together with other artists, including Alicia Keys, Beyonce, Madonna and Kanye West.