The Bahraini foreign ministry urged Shiite Iran to keep out of the affairs of the Sunni-ruled but Shiite-majority nation for the sake of the security of the whole region.
"The ministry condemns the statement by the Iranian Minister of Foreign Affairs, Mohammad Javad Zarif, regarding investigations with a Bahraini citizen, involved in a number of illegal actions and violations," it said.
"It also expresses surprise and regret over Iran's adoption of such hostile policies that steer it away from the concept of good neighbourliness with the countries of the region, urging it to look after the interests of the brotherly Muslim Iranians who suffer from flagrant violations of human rights and freedom of expression."
Iran urged Bahrain on Wednesday to free Salman, head of the Shiite movement Al-Wefaq, which boycotted a parliamentary election in November having dismissed it as a farce.
Signup to our newsletter and follow us on Facebook and Twitter!
Shiite Iran has been accused of interfering in Bahrain's affairs ever since the Sunni ruling family crushed month-long protests led by Al-Wefaq in 2011 seeking an elected government.
Strategically located just across the Gulf from Iran, Bahrain is home to the US Navy's Fifth Fleet.
Washington too expressed deep concern on Wednesday about Salman's detention, warning that it could only inflame the persistent violence that has gripped the kingdom since 2011.
But the Bahraini authorities have repeatedly rejected Al-Wefaq's demand for an elected prime minister to replace the current government dominated by the royal family, and accuse its leader of seeking regime change by force.