SAM Allardyce is suing an Irish property developer once dubbed “a thug in a suit” for £3.5million.
Ex-England boss “Big Sam” and his wife claim they paid John Kelly £883,000 to buy and do up two Surrey mansions.
But the deal — which also included buying £100,000 in Bitcoin — fell through, a High Court writ claims.
Now lawyers for the couple say Kelly, 60, has since “failed to account” for their investment.
The developer, of Windsor, Berkshire, built a property empire in Dublin in the 2000s worth millions.
He paid around £350,000 to Girls Aloud to perform at his step- daughter’s 21st birthday.
In 2009 he told an Irish court he owned a helicopter, a yacht in Marbella, a Bentley and an Aston Martin.
But his fortunes collapsed and in 2012 he claimed he was under police protection after paramilitary threats.
In 2013 convicted fraudster Thomas Byrne accused Kelly, his former business partner, of being a “thug in a suit” and “vampire-like” while on trial at Dublin’s central criminal court.
The writ by the Allardyces at London’s High Court, against him and his wife, Mary O’Connor, claims they handed over £883,000 to Kelly between 2017 and 2019.
The money was allegedly meant to be used to buy the properties in Woking and Cranleigh, which would be developed and sold for profit.
Kelly also pledged to use the cash to buy 34 units of Bitcoin for £100,000. But the writ accuses him of failing to pay the Allardyces “any of the sums owed to them”.
It says Kelly even rang 68-year-old Allardyce, who managed the England football team in 2016, and told him the Bitcoin deal had gone “belly up”.
The writ is for £650,000, plus £2.5million in interest, with £1,417 per day in interest until the claim is concluded.
It is also demanding 34 units of Bitcoin be returned or £511,200 in compensation.
The writ also reveals Kelly committed to pay £200,000 to Mark Curtis, understood to be Allardyce’s football agent, by February 2019.
Kelly’s defence is yet to be made public.