A man questioned today about the Omagh bomb massacre was later released without charge.
The PSNI said it was the second time the 37-year-old from south Armagh had been detained for questioning over the August 1998 attack.
After being held for several hours at Antrim he was freed.
Twenty-nine people, including a woman pregnant with twins, were killed in the no warning Real IRA car bombing in the Tyrone town in August 1998.
More than 300 other people were injured.
A second man, also from south Armagh, is expected to be charged later this month in connection with the atrocity.