Police investigating the murder of German backpacker Inga Maria Hauser have arrested two men.
The men, aged 58 and 61, were arrested in Loughguile, County Antrim, early on Monday morning.
Ms Hauser, 18, went missing after she arrived in Larne on a ferry from Scotland on 6 April 1988.
Her body was found two weeks later in a remote part of Ballypatrick Forest, near Ballycastle, County Antrim.
Police renewed their appeal for information last month - the 30th anniversary of the murder.
On 1 May they said they had received the results of further DNA testing.
Police believe Ms Hauser died shortly after she arrived in Northern Ireland, having been subjected to "a vicious and ruthless assault".
On Monday, Det Ch Supt Raymond Murray renewed his appeal for information.
"If there are any witnesses still out there with any further information which might help police then I would ask them to come forward now and speak to detectives," he said.
"Even if there are people who know what happened but have stayed silent out of friendship or family loyalty, it is still not too late to come forward and tell us what you know.
"Failure to do so can be a criminal offence in itself and surely it would be better to come to police and discuss what happened rather than take the risk we will come to you."