The Democratic Unionist Party's Jeffrey Donaldson made the comments during an interview on the BBC's Talkback programme.
Mr Donaldson was speaking about the use of agents within paramilitary organisations during the Troubles.
On Thursday, an investigation into the Loughinisland massacre in 1994 found that there was collusion between some police officers and loyalist gunmen.
Mr Donaldson said he owed his life to the informer who told police about a plan to murder him at his home in Moira.
He said: "Because of that information, steps were taken to safeguard my life.
"I will forever be indebted to that person."
Mr Donaldson added that his party would not "turn a blind eye" to wrong-doing.
"People have a right to justice and I will stand by anyone who has lost a loved one and is seeking justice," he said.
"No-one is above the law."
A Northern Ireland MP has said a republican informer saved his life.