An individual who laced treats with sedative and gave them to children at a youth camp in the area has confessed to sexual offences against two young males both between nine and ten.
The accused was taken into custody after eight minors and one adult became sick at the facility in July.
The 76-year-old, from that region, pleaded guilty to a series of 17 offences when he stood at Leicester Crown Court on Friday.
However, he disputed one particular crime he was charged with, which was concerning a nine-year-old boy.
The defendant was kept in jail ahead of a additional proceeding on late November.
'Sweet game'
Mary Prior KC, presenting evidence, described the defendant's actions to the judicial body.
She stated his targets were under-privileged children who were attending a youth camp which he ran.
The man conducted a "treat game" with the minors, the prosecutor said, in which he would access the sleeping quarters when they were getting ready for bed and request they to ingest treats "as quickly as they can".
She told the court Ruben had played this game with the children "repeatedly", and children had previously fallen ill the following morning.
She said Ruben had been capable of justifying this over a long period as the children being "overexcited from fun", until his family member had suspicions in recently.
The prosecutor continued: "This year his stepson had suspicions about the situation, with valid cause.
"They resolved" to examine in the defendant's belongings."
Mrs Prior KC explained materials including lubricant, Vaseline and medical needles were discovered, and his stepchild alerted the authorities about his suspicions.
She said Ruben continued to conduct the "candy game" with six children that time - Saturday 26 July - and they were all ill the subsequent day.
"The police had not arrived by that stage," she stated further.
The regulatory agency, the investigative body, earlier informed that it was reviewing the police response of the events.
The prosecutor said the youngsters were unable to walk properly due to their condition, so the stepson called the police once more.
She said the defendant then engaged in the "treat game" in a room of five minors.
