Former DUP leader Ian Paisley has been admitted to hospital for tests.
The party stalwart was treated for a heart condition last year and has been taken into the Ulster Hospital, near Belfast this weekend, a spokeswoman for the hospital said today.
"He is in hospital for tests but he is in good spirits and his family has asked for privacy," she added.
Mr Paisley, 87, now known as Lord Bannside, led the DUP into power-sharing at Stormont with Sinn Fein in 2007.
In February 2012, the 87-year-old spent a week on a life support machine suffering from heart failure.
He later returned to public life after recovering.
The previous year he had a pacemaker fitted at St Thomas' hospital in London after falling ill at Westminster. Paramedics had to revive him following his collapse in parliament.
Mr Paisley stood down as Northern Ireland's first minister in 2008 and ended 60 years of full-time ministry in January 2012.
The veteran unionist and fundamentalist Protestant preacher has been a colossus of Northern Ireland politics.
He was an MP for North Antrim and a divisive figure at a time when an armed conflict which killed thousands was at its worst.
Mr Paisley established the DUP in 1971 and opposed every attempt by successive British and Irish governments to create a power-sharing government between nationalists and unionists in Northern Ireland.
But in a dramatic change of heart after the St Andrews agreement in 2006 he indicated that the DUP would share power with their former enemies in Sinn Fein. As a result, he and senior ex-IRA member Martin McGuinness became first and deputy first ministers of Northern Ireland.
They established an unlikely rapport, gaining the nickname "the Chuckle Brothers" because at public events they were often seen smiling and joking together.
Since he stepped down as first minister Mr Paisley has retreated from public life and preached his final sermon as leader of the deeply conservative Free Presbyterian Church which he founded in the 1960s.
When he moved aside as DUP leader he was succeeded by his long-time deputy Peter Robinson.