Iran denied on Wednesday claims by Saudi Arabia that alleged spies it arrested were linked to the Islamic republic, and criticised the kingdom for publicising such allegations.

Foreign ministry spokesman Abbas Araqchi said the reports were "false," maintaining Iran's position of completely rejecting the accusations.

On Tuesday, Saudi authorities said they had detained 10 more suspects, bringing to 28 the number of people accused of spying for Iran, and one of whom is Iranian.

They said the ring had "direct links" to Iran's intelligence services and was busted in March.

Araqchi asked the Saudis to permit consular access to the Iranian detainee.

The foreign ministry summoned the Saudi charge d'affaires in March, expressing the country's strong protest over the allegations.

"We ask the Saudi government to pursue the issue through the correct path instead of resorting to a (negative) media campaign," the ISNA news agency quoted him Araqchi as saying.

Saudi Arabia's ultra-conservative Sunni Muslim rulers have long had strained ties with Iran, a predominantly Shiite country. These deteriorated further in early 2011 after a Saudi-led military intervention crushed Shiite-led pro-democracy protests in neighbouring Bahrain, run by a Sunni dynasty.

Also since early 2011, mainly Shiite towns in Saudi Arabia's Eastern Province have seen sporadic protests and confrontations between police and residents complaining of marginalisation.

There are an estimated two million Shiites in Saudi Arabia out of a population of about 27.5 million people.

In March, 135 Saudi Shiites, among them 36 clerics, urged the government to free members of the alleged spy ring, accusing it of using sectarianism to settle foreign scores.