A Dutch investigating judge on Friday refused to prolong the detention of a radicalized man who is suspected by prosecutors of "possible involvement in making preparations for a terrorist crime."

The 29-year-old man, whose identity has not been released, was detained a week ago outside the PSV Eindhoven soccer stadium where thousands of fans were attending a pop concert by Dutch singer Guus Meeuwis. Police said the man was known to be radicalized, did not have a ticket for the concert and was making video recordings.

Court spokeswoman Ilse Westenenk said that the investigating judge ruled that there was insufficient evidence against the man to justify holding him for a further two weeks. It was not immediately clear if prosecutors would appeal.

Dozens of extra officers were deployed around Eindhoven following the man's arrest, but police said there was no direct threat to concertgoers.

The man's arrest came amid heightened security around many concerts following the May 22 bombing at an Ariana Grande concert in Manchester that killed 22 people and the bomber.