The Romanian government has taken emergency measures to suppress growing discontent among the two-million-strong Hungarian community in Romania, according to a former close aide of President Nikolai Ceausescu.

The charges by Karoly Kiraly, a former high Romanian Communist Party official, reflect increased tensions in Romania as well as what appears to be an unprecendented challenge to Ceausescu's authority.

Kiraly also said in an interview that 16 prominent Romanian Communist officials have associated themselves with an open letter in which Kiraly denounced the Romanian government for suppression of minority rights.

Among those backing the protest Kiraly cited former prime minister Ion Gheoghe Maurer; the present deputy prime minister, Janos Fazekas, and several other members of the Romanian Central Committee and parliament.

Kiraly said that the Romanian government has responded by taking emergency measures to supress growing discontent among Romania's ethnic minority. He spoke of the massive deployment of troops in Transylvania, where most Hungarians live, and house-to-house searches, interrogations and other forms of harassment.

Apart from Maurer, all other figures who reportedly associated their names with the protest are of Hungarian background.

But such an endorsement of a protest movement here is without precesdent. The question of ethnic rights has long been a source of covert dispute between the two Warsaw Pact neighbors. Publicly, however, all Soviet bloc countries have contended that such issues have been resolved.

The sudden upsurge of protest among Romania's minority and the public backing of it by the Hungarian Communist government has posed a serious domestic challenge to Ceausescu.

Karoly spoke to three Western journalists in defiance of official warnings against contacts with the foreign press.

The interview took place in Caransebes, a town of some 27,000 people where Kiraly is in internal exile in an attempt to isolate him from his supporters in Transylvannia -- the mountainous region of central Romania and the setting for Bram Stoker's spinechilling novel Count Dracula.

At one point, Kiraly's German wife Helga switched off the lights in the kitchen of their sparsely furnished three-room cottage to prevent a curious neighbour from seeing the journalists gathered around the table.

Soft-spoken and looking younger than his 47 years, Kiraly described what happened after he attempted to raise minority grievances in a series of letters to Romanian leaders. He is of Hungarian origin himself.

Kiraly's formidable cateloge of allegations included the closing of Hungarian universities and schools, the suppression of the Hungarian language and culture, and the appointment of Romanians to nearly all key posts in towns with a Hungarian majority.

"For years the Romanian government has had a policy of the forced assimilation of all minorities -- not just Hungarians, but also Germans, Serbs and others," he said.

The most serious repercussions began at the end of January following the publication of details of his appeals in Western newspapers.

Kiraly said: "Suddenly emergency police measures were taken throughout Transylvannia. Around a thousand security men were drafted into my hometown of Tirgu Mures alone. There were armed patrols and special civilian brigades in the streets. Tens of thousands of people were watched and many homes were searched for copies of my letter. This action is still continuing, although on a reduced scale."

Kiraly was summoned to Bucharest for talks with four top officials including Ilie Verdet, Ceausescu's righthand man, and the minister of the interior, Teodor Coman. He was accused of being a traitor to Romania, threatened with a trial and expulsion from the Communist Party, and asked to denounce his own appeal as the fabrication of the CIA and Radio Free Europe. He refused.

He was ordered to leave Tirgu Mures with his wife and five-month-old baby. He said his friends were harassed in the street, his house was kept under a 24-hour watch, and he was followed by plainclothes policemen.

Asked what he thought were the reasons for this government reaction, he replied quietly: "They know that what I wrote is true." An official Romanian spokesman has described Kiraly's allegations as "lies, lies, lies."

Kiraly himself is an insider who knows how the system works. As an alternate member of the political executive committee from 1968 to 1972, he was at the summit of the Romanian leadership. In 1970 he accompanied Ceausescu to Moscow to attend the Lenin centenary celebrations. He is still a party member and deputy president of the Hungarian Nationality Council. He stresses that he remains committed to his social ideals.

His protests have also received the support of key leaders of the Hunggarian minority. Apart from Fazekas, they include the vice-president of the Romanian parliament, Gyorgy Puskas, central committee members, writers, and the editors of the two most prominent Hungarian literary reviews in Romania.

Kiraly claimed that nearly all Hungarian intellectuals agree with his views and many ordinary people, including Romanians, had expressed support through handhakes, telephone calls, and letters.

By alleging mistreatment of national minorities, Kiraly has struck one of the most sensitive chords in Romanian politics. Underpinning Ceausescu's staunchly independent foreign policy is an attempt to build a strong unitary state at home creating the image of "an island of Latins surrounded by a sea of Slavs."