Saudi Arabia said on Tuesday that people it arrested on suspicion of spying this month had direct links to the intelligence services of Iran.
“Preliminary investigations, physical evidence which has been collected and statements from the accused in this case have shown a direct link between members of this cell and Iran's intelligence apparatus,” said a security spokesman for the Interior Ministry quoted by the official news agency.
He said Iranian intelligence had paid the suspects “in exchange for information and documents about important sites”. The investigation is ongoing, he added.
Riyadh announced a week ago it had arrested 16 Saudis, an Iranian and a Lebanese on suspicion of spying.
Iran denied on Sunday that it was linked to spying in Saudi Arabia.
The allegation marks an escalation in friction between the two major oil producers, which face each other across the Gulf.
Riyadh has also accused an unnamed foreign power, which officials have privately named as Iran, of stirring unrest among its Shi'ite minority, something Tehran has denied.
Saudi Arabia also points to an alleged Iranian plot, announced by United States Police in 2011, to assassinate the Kingdom's Ambassador in Washington. Iran denied that too.
Members of Saudi Arabia's Shi'ite Muslim minority said the arrested men were from their community and expressed doubt over the veracity of the spying charges.
The 16 Saudis arrested included a Pediatric Doctor, a University Professor and a Banker as well as two well-known clerics. Relatives and friends of some of those arrested said they did not believe the men had strong political views.