Originally Published: 28 SEP 21 14:10 ET

By Manveena Suri, CNN

(CNN) -- Police in the Netherlands have arrested and released a former member of a far-right political party after Prime Minister Mark Rutte's security detail suspected him of behaving suspiciously, according to the Public Prosecutor's Office of the Hague.

Arnoud Van Doorn, who once served as a senior political adviser for populist Freedom Party leader Geert Wilders, was arrested by the Royal and Diplomatic Security Service on Sunday in The Hague, a spokesperson for the city's Public Prosecutor's Office told CNN.

The arrest comes amid reports from the Dutch media outlet De Telegraaf and Reuters that Rutte's security has been heightened following fears he may be the target of an attack or kidnapping by a criminal gang. CNN has not been able to independently confirm the reports.

Van Doorn was released on Monday but "remains a suspect," in connection with "trying to provide information to others to prepare a serious crime," according to the Public Prosecutor's Office.

"The man acted suspiciously so he was arrested and released later, and the investigation must show what exactly was going on," another spokesperson said in an emailed response to CNN, adding that the investigation has not yet been completed.

In a statement issued to CNN, Van Doorne's lawyer, Anis Boumanjal, dismissed the allegations, saying they are "devoid of reality" and "not supported by facts."

"The DKDB based the arrest on the fact that my client exhibited suspicious behavior but have otherwise left us in the dark as to what exactly is understood by said suspicious behaviour," the statement says.

It adds Van Doorn was in the same area as Rutte because his mother lives there and he visits the same cafe as the Prime Minister. He also apparently visited a fitness center the Prime Minister belongs to, inquiring about rates and operating hours, the attorney said.

CNN has reached out to the Prime Minister's office for comment.