(Bloomberg) -- The co-founder and former chief operating officer of telecommunications group Altice, Armando Pereira, has been detained for questioning in Portugal as part of a sweeping investigation into alleged corruption. 

Pereira was among those detained in a Portuguese criminal investigation, his lawyer Pedro Marinho Falcao told Bloomberg News in an interview on Monday. Last week, local authorities said three people were detained during a series of raids of homes and offices across the country, related to a three-year investigation into corruption, tax fraud, forgery and money laundering.

Pereira, who co-founded Altice Group with Patrick Drahi and Bruno Moineville in 2002, no longer holds executive roles at the company.

Pereira’s lawyer said his client was detained on Thursday and remains in custody, waiting to be questioned by a judge.

Prosecutors suspect that procurement decisions taken at Altice, Portugal’s largest telecommunications operator, were rigged in a way that harmed the group’s own companies and competitors, Portugal’s Central Department of Criminal Investigation and Prosecution said in a statement on Friday.

The company’s Portuguese unit said its offices were among those searched in relation to an investigation of individuals and entities outside of Altice Group. It has started an internal probe of its procurement and real estate sales, and has suspended payments to entities targeted by the authorities.

It also said in a statement on Monday that Alexandre Fonseca, the group’s co-chief executive and chairman of its units in the US and Portugal, had temporarily stepped down to “fully protect and safeguard” the company amid the investigation into events that occurred while he was CEO of the Portuguese unit. There is no evidence to suggest that Fonseca is under investigation himself at the moment.

Fonseca’s lawyer Rogerio Alves wasn’t immediately available to comment via email or phone.

Following news of Fonseca’s suspension, bonds issued by Altice Finco maturing in 2028 fell 7.1 cents on the euro to 56.8 cents, set for the steepest daily drop since March 2020, according to data compiled by Bloomberg.

--With assistance from Libby Cherry.

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