The man, was detained in Przemysl - near Poland's border with Ukraine. | VALENTYN OGIRENKO

Poland has arrested a Spanish national of Russian origin on suspicion of participating in foreign intelligence activities, the Internal Security Agency (ABW) said on Friday.

The man, identified as an agent of Russia's military intelligence agency (GRU), was detained in Przemysl - near Poland's border with Ukraine - on the night of Feb. 27-28, ABW said in a statement.

His Spanish lawyer named him as Pablo Gonzalez, a reporter for several Spanish media including online newspaper Publico and TV station La Sexta.

Both outlets have recognised Gonzalez as having worked with them.

"After 4 days, we have just been informed by the Consulate of Spain in Poland that Pablo Gonzalez is charged with the crime of espionage under article 130.1 of the Polish Penal Code and is in provisional detention in Rzeszow prison," lawyer Gonzalo Boye said on Twitter.

Boye told Reuters he was trying to get in contact with Gonzalez but had not yet been given access to his client. He demanded his immediate release.

Spain's Foreign Ministry said it had been informed by Polish authorities of the charges but could not provide any details. The ministry will offer consular assistance and provide whatever help it can, as with all Spaniards detained abroad, it said.

ABW said the man carried out operations to benefit Russia, and travelled in Europe and elsewhere under cover of being a journalist.

"Before his detention, he was planning to go to Ukraine in order to continue his activity," it said.

The man will remain in custody for three months initially, and faces up to 10 years in prison if found guilty, the agency said.