A husband and wife from Northampton have been convicted of 94 drug and sexual offences perpetrated against a group of children, with some as young as 11, over the course of 10 years.

Nicholas Taylor, 47, was found guilty of 62 charges, while 42-year-old Joan Taylor was found guilty of 22 offences, with their charges including rape, indecency with a child, and supply of class A drugs. They will be sentenced in May.

The pair were described as “master manipulators” by officers who worked to bring them to justice. “It is very clear that Nicholas Taylor is a very dangerous, depraved, individual who used threats of violence alongside crack cocaine to sexually abuse children,” said Adam Pendlebury, a Northamptonshire force detective inspector, who oversaw the investigation.

Joan Taylor. Photograph: SWNS.com

He added: “It would be easy to suggest that he forced and bullied Joan into committing offences but the court has heard that she was a more than a willing accomplice. The Taylors were master manipulators who used crack cocaine to force their victims to engage in sexual activity against their will, and their actions have had a devastating impact on their victims’ lives.”

Both had pleaded guilty to other offences before the trial began at Leicester crown court in February.

The crimes were committed between 1996 and 2006 against boys and girls. Each of their 11 victims was aged 16 or younger at the time of the incidents and each gave evidence at the trial. Northamptonshire police said the investigation into the Taylors began in 2014 and was the largest of its type in the force’s history.

Det Con Cathy O’Connor, who led the investigation, said: “The courage of the victims, who went from giving us small bits of information to attending crown court to face their abusers, has led to today’s positive result.”

The National Society for the Prevention of Cruelty to Childrencalled the “sheer number of sickening crimes” committed by the couple “truly horrific”.

A spokesman for the charity said: “Both Nicholas and Joan Taylor used and abused children for their own twisted pleasure and their sickening actions, will have had hugely damaging effects on their many young victims. An utterly vile aspect of this case is that they introduced vulnerable children to drugs and then forced them to commit sexual acts. Their victims’ bravery in speaking out has helped bring this couple to justice and we hope [the victims] are receiving all possible support to rebuild their lives.”

During the trial, the jury heard that Nicholas Taylor was a bullying figure, who liked to think of himself as a local hard man. According to the Northampton Chronicle and Echo, the prosecutor David Herbert QC said Taylor was “violent controlling bullying and manipulative”. Herbert said: “He was one of those people who wanted to have the reputation for being on his estate as a hard man.”

The court heard that the couple plied their victims with crack cocaine to make them more compliant with the sexual offences they carried out against them.