The scene following an IRA car bomb blast in Hyde Park, London, which killed four Royal Household Cavalrymen and seven horses, as they rode through the central London park to attend the Changing of the Guard in July 1982. Credit:PA News Mr Downey is understood to be the first OTR recipient to be charged with terror related offences since the House of Commons Northern Ireland Committee found that the scheme had “distorted the legal process”.He has always denied any involvement in the Hyde Park attack, in which Trooper Simon Tipper, 19, Lance Corporal Jeffrey Young, 19, Squadron Quartermaster Corporal Roy Bright, 36, and Lieutenant Anthony Daly, 23, were killed.The IRA car bomb exploded as they made their way from their Kensington barracks to a Changing Of The Guard ceremony at Horse Guards Parade. The men, both members of the Ulster Defence Regiment (UDR) died when an IRA bomb exploded in a car they were checking on the Irvinestown Road, Cherrymount, Enniskillen on August 25, 1972.Mr Downey was held on suspicion of aiding and abetting an explosion. Following yesterday’s hearing he was remanded in custody pending a bail application on Thursday.At the Hyde Park bombing trial judge Mr Justice Sweeney ruled that Downey’s arrest at Gatwick Airport, as he passed though the UK on the way to a holiday, represented an abuse of process.Mr Justice Sweeney put a stay on any future prosecution in relation to the Hyde Park case, prompting a wider inquiry into the OTR scheme. The convicted IRA member whose trial over the Hyde Park bombings collapsed in controversial circumstances has become the first recipient of a so-called ‘comfort letter’ to be charged with terrorism offences.John Downey, 66, appeared in court in Dublin on Tuesday accused of murdering two soldiers in 1972, a decade before the park bombing killed four members of the Household Cavalry.The Hyde Park trial collapsed after it was revealed he had received a written assurance from former prime minister Tony Blair’s government that he was not actively wanted by the authorities.The letter was issued under the terms of the controversial On The Runs (OTRs) scheme as part of the Good Friday agreement to bring peace to Northern Ireland.But in a sudden turn of events Mr Downey was arrested under a European Arrest Warrant at his home in County Donegal on Monday evening, as part of a joint operation with the Police Service of Northern Ireland (PSNI).Mr Downey appeared at the Criminal Courts of Justice to face extradition proceedings after prosecutors in Northern Ireland decided there was sufficient evidence to prosecute him for the murders of Lance Corporal Alfred Johnston, 32, a father of four, and Private James Eames, 33, a father of three, in Co Fermanagh. Mr Downey is now being sued for compensation in the civil courts by the families of the four troopers, who are asking the High Court in London to rule he was liable for their deaths.Announcing Monday’s arrest, Detective Chief Inspector John Caldwell, from the PSNI’s Major Investigation Team, said: “The PSNI has been liaising closely with An Garda Siochana and today’s arrest demonstrates the benefits of joint working between police forces and other national partner agencies. The PSNI investigation into these murders remains active.”A spokesperson for Northern Ireland’s Public Prosecution Service (PPS) said: “Following careful consideration of all available evidence, a decision has been taken to prosecute one person for the offence of murder and for aiding and abetting the causing of an explosion.”As proceedings are now live and before a Court we will not be making further comment on this case at this point.”The families of the two murdered soldiers are being kept informed of developments.Yesterday’s hearing came after this newspaper revealed how Irish Land registry documents showed that Mr Downey removed his name from ownership of this second house, worth £300,000, on June 7 last year, in an apparent attempt to avoid paying any damages awarded against him. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.