Married biology teacher Kenneth Topham ( pictured ) got close to the ‘ naive ’ girl in after-school study sessions at Worksop College . A private school teacher has been jailed for having a year-long sexual relationship with a teenage pupil under the noses of senior staff . Married biology teacher Kenneth Topham , 51 , got close to the ‘ naive ’ girl in after-school study sessions at Worksop College . He began grooming the girl , who can ’ t be identified for legal reasons , in March 2013 , while she was a pupil at the £9,000-a-year school in Sherwood Forest , Nottinghamshire . Last night the school was condemned for failing to act despite reports of inappropriate behaviour from several pupils and fellow teachers early on in the affair . Topham was finally arrested after scores of ‘ sex texts ’ sent by him to the girl were found on her phone in May 2014 and headmaster Gavin Horgan called the police . A former pupil accused the school of a cover-up , saying : ‘ They knew what was going on , but refused to do anything about it . 'It is shocking that he was allowed to continue teaching and behaving like this when so many of us complained. ’ Topham , a father of two who was also a foster carer to several children over the past decade , would meet the victim after school in his classroom . There they repeatedly engaged in sexual activity which fell short of full sex , Nottingham Crown Court heard yesterday . The teacher – a housemaster who would stay overnight at the school – admitted five offences of wrongful sexual activity and four of incitement by a person in a position of trust . He was sentenced to 18 months in prison yesterday . Suspicions were first raised in the summer of 2013 , when the girl was spotted arm-in-arm with Topham and wearing his jumper . Afterwards , a school housemistress had an ‘ informal discussion ’ with Topham reminding him of boundaries and also spoke to the girl . They received another warning that November after being seen with their arms around each other at a school prom . He began grooming the girl , who can ’ t be identified for legal reasons , in March 2013 , while she was a pupil at the £9,000-a-year school ( pictured ) in Sherwood Forest , Nottinghamshire . The private school teacher has been jailed at Nottingham Crown Court ( pictured ) for having a year-long sexual relationship with a teenage pupil under the noses of senior staff . At Christmas Topham told the victim he loved her and in January 2014 a teacher saw them bouncing on a trampoline together . The school ’ s deputy head then spoke ‘ in detail ’ to Topham about the relationship and the victim ’ s parents were informed . The teenager , who was described by her housemistress as ‘ a very quiet girl and not worldly-wise ’ is now at university . ‘ I feel let down , hurt and stupid for allowing him to use me , ’ she said in a brief statement to the court , adding that he had ‘ ruined ’ what should have been ‘ fond memories of school ’ . Judge Michael Pert QC told Topham he had ‘ exploited a naive teenager ’ . A spokesman for the school said that because of the legal proceedings it could only share ‘ very little information ’ with parents , adding : ‘ We have always taken our safeguarding responsibilities very seriously and ‘ while the College acted swiftly when it became aware of the issue.. we have undertaken a review ... of every aspect of our practice ’ .
Topham got close to the girl during after-school study sessions . Began grooming her while she was at Worksop College , Nottinghamshire . School condemned for failing to act after students and fellow teachers reported inappropriate behaviour . Arrested after scores of ‘ sex texts ’ sent by him were found on girl 's phone . Admitted charges of wrongful sexual activity and incitement by a person in position of trust .