Ex-BBC presenter Benjamin David Thomas admitted 40 sex offences against kids and adults.
He pleaded guilty to the offences, which happened when he was working as a church pastor.
Thomas previously worked for BBC Wales.
His crimes were described as “an awful breach of trust” in court.
Thomas, 44, from Flint in North Wales, had been a respected pastor for many years.
Before becoming a pastor, he was a reporter and presenter on Ffeil, a Welsh language news show for young people, and Wales Today.
He admitted 10 counts of sexual activity with a child, eight sexual assaults, and four attempts to commit sexual assault.
He also pleaded guilty to nine indecent assaults, seven counts of voyeurism and two counts of making indecent videos of children.
They were made as early as 1990 and as recently as last year.
Thomas committed the sex offences in Wales, Shropshire, London and Romania.
It is an awful breach of the trust placed in him by the victims and their families.
He appeared in Mold Crown Court, where he will appear again to be sentenced on August 18.
He was granted bail until then.
Judge Niclas Parry warned a “significant custodial sentence” was inevitable despite his early plea, North Wales Live reported.
Serious sexual abuse
North Wales Police DC Lynne Willsher said: “Ben Thomas’ offending involved the serious sexual abuse of vulnerable young children by a religious leader.
“It is an awful breach of the trust placed in him by the victims and their families, and I cannot begin to imagine what impact the revelation of his offending has had on them.
“Today in court, Ben Thomas has admitted perpetrating 40 sexual offences.
“As a result of this, his victims have been spared the harrowing ordeal of a lengthy trial.
“North Wales Police are very grateful for the strength and courage shown by all victims and their families; this has greatly assisted our investigation to ensure justice has been done today.
“I am also grateful to the Evangelical Church and their safeguarding team for their assistance during the investigation.”
Thomas left the BBC in 2005 to preach on the streets of London.
He then returned to Wales in 2008 as pastor of the Criccieth Family Church in Gwynedd.
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