A Russian man suspected of spying at the Norwegian parliament was released from prison on Friday after Norway's intelligence service withdrew an appeal against the decision.
Mikhail Bochkarev, 51, was arrested on September 21 at Oslo airport after attending a seminar in Norway's parliament, accused of having collected data on the building and its network.
Television footage showed Bochkarev leave Oslo prison on Friday in a car from the Russian embassy.
His release came after a Norwegian judge ruled on Thursday that investigators had failed to substantiate their case.
The PST intelligence service initially appealed the decision but on Friday the agency made a U-turn.
"The PST has decided to withdraw its appeal... He is released today," the agency tweeted without an explanation.
Russia had denounced the charges against Bochkarev as "false" and "absurd".
He remains under investigation but is free to leave the country, the PST said.
"This was the only solution. It shows that the PST also realises that the suspicions are unfounded," Bochkarev's lawyer, Hege Aakre, told NRK radio.
There had been speculation that Bochkarev might be used as leverage in efforts to obtain the release of a Norwegian held in Russia on suspicion of spying, although the PST has denied any connection between the two cases.
Frode Berg was arrested in April and is still waiting trial. Berg admitted to having helped the Norwegian intelligence services by acting as a courier several times.
"The possibility of an exchange has now definitely gone," Berg's Norwegian lawyer Brynjulf Risnes told Norwegian news agency NTB.
"The release of Mr Bochkarev is a lost opportunity for us," he added.
Norwegian officials regularly accuse Russia of attempted hacking and espionage.