A photographer with Celtic Football Club has admitted a charge of indecency against boys aged as young as 10.
Cullen was employed by Celtic for nearly 30 years
Glasgow Sheriff Court heard that pictures taken of young boys were hidden in a store room at Celtic Park for nearly 20 years by John Cullen.
The photographs were found by cleaners who reported the discovery to their bosses - who then called the police.
Cullen, 49, pleaded guilty to a charge of lewd and libidinous behaviour. He will be sentenced next month.
The court heard on Friday that in May 2002, cleaners were clearing out a store room at the club where Cullen kept his camera equipment.
They found a black bag and opened it to check if it was rubbish.
But the staff found bundles of black and white pictures of young boys who were either nude or semi-nude.
They reported the find to management and the police were called in.
Cullen, of Shawbridge Street, Pollokshaws, Glasgow, was questioned about the 250 pictures.
He admitted inviting the children to a house in Glasgow between January and December 1982 before getting them to pose for the camera.
The pictures were then locked away in his Celtic Park store room for years.
Cullen first appeared in court last October, but the case was repeatedly adjourned to try and identify the youths.
Despite the help of Scotland Yard's special paedophile unit, their identities were never discovered.
Liz Ramsey, prosecuting, said it was agreed the boys who were photographed were aged between 10 and 13.
Cullen, who worked for the official club magazine Celtic View, was dismissed from Celtic Park in June 2002 after nearly 30 years.