The principal of Antrim Grammar School has paid tribute to former teacher Robert Flowerday who was found dead on Sunday.
Last night police revealed they had launched a murder investigation after his body was discovered at his home in Crumlin, County Antrim.
IN PICTURES: Tributes to murdered ex-teacher Robert Flowerday
The ex-Maths teacher, 64, was last seen alive leaving Dundrod Presbyterian Church on Sunday.
Antrim Grammar principal Jenny Lendrum said: "The entire Antrim Grammar School community is mourning the loss of former teacher Mr Robert Flowerday.
"Mr Flowerday was a teacher in Antrim Grammar School from 1978-2004 and during that time he touched so many lives in his role as teacher, colleague and friend.
"He was a talented mathematician and was dedicated to every pupil that he taught. He believed in them and always worked tirelessly to ensure that every pupil achieved their full potential. To that end he was successful.
"He left Antrim Grammar School in 2004 to pursue personal tuition for pupils in Mathematics, Physics and Chemistry as well as preparing pupils for transfer. As a result, he continued to have a positive impact on the lives of many and ensured they enjoyed success.
"He loved Antrim Grammar School and kept in touch with staff members as well as tutoring pupils right up until last week. The news of his death has impacted everyone. There has been an outpouring of emotion from current and past teachers and pupils within the school, through phone calls and through social media.
"A special assembly took place today in memory of him and all within the school community took time to acknowledge all that he had given to Antrim Grammar and the wider community throughout his teaching career.
"Our thoughts are with his family at this difficult time and his Antrim Grammar School family will continue to remember the wonderful, genuine, gentle and caring man that was Mr Flowerday."
On Tuesday police said a 33-year-old man has been arrested on suspicion of murder following the death of Mr Flowerday.