An IT executive stood next to his estranged wife at their daughter's school sports day just hours before he allegedly murdered her and their two children at the family's £1.3million home and fled Britain.Mark Tshuma, who earned £100,000, was seen in CCTV footage at Heathrow airport on Saturday where he took a flight to his native Zimbabwe after allegedly killing his whole family.The bodies of his wife Zandile Tshuma, 42, and their daughters Natalie, 15, and Nala, five, were found in the family's property near Bedford on Monday.But just the day before he fled to southern Africa, Tshuma had been acting normally, a friend has said - and even attended the summer family event with his wife.Andrew Southam, who services the swimming pool at the family's home, said: 'I saw Mark on Friday. He was fine.'He was looking forward to his daughter's sports day and praying that the weather would hold out, because previous sports days had been cancelled. So he was really looking forward to that.'Both daughters attended local private schools, Natalie was at the £20,000-a-year Bedford Girls School while Nala attended Pilgrims Pre-Preparatory School - but it remains unclear which of the murdered sisters had their sports day on Friday.Mr Southam, 64, said had been at their house to service the pool, and that as usual, Mr Tshuma had seemed a happy family man. Ndodana Mkhanyisi Tshuma was seen on CCTV at Heathrow on Saturday as he fled to Zimbabwe - before the bodies of his wife and two daughters aged five and 15 were found at their home on Monday Zandile Tshuma, left, was discovered with her two children, five-year-old Nala (centre) and Natalie, 15, at their family home in Bedfordshire on MondayThe family lived in a detached house in an affluent suburb of Bedford. Police had to force entry on Monday after concerns were raised for the occupants' welfareHe said: 'He was a lovely guy, always smiling, very polite, spoke well.'Another parent told the Mail: 'Mark was at the Sports Day on Friday with Zandie. It was known they were divorcing.' The following day Tshuma was seen dressed in black, with a blue sweater and Apple watch, clutching bottles of Coke and water, holding a boarding pass and pushing a suitcase as he went through an E-gate at Heathrow before flying to Zimbabwe.Friends have revealed he and his wife were in the process of divorcing and had recently got a valuation of their luxury home to put it on the market as part of separating.Tshuma had told friends he did not want a divorce as he could not live without Zandile and their children.One friend, who did not want to be named said: 'They had been having marriage problems for quite a while. Their relationship had broken down and Zandile had had enough.'She was a great mother and wife and a lot of the problems were down to Mark's controlling behaviour.'She told us that they'd had the house valued and had decided to separate. She wanted to start a new life with the kids.'Another friend added: 'The marriage was over and Zandile wanted to move on without Mark. She was a very clever woman who worked in IT and was more than capable of creating a new life for herself with the girls. Zandile, a mother-of-two, was a high achieving director specialising in financial crime, fraud investigations and anti-money laundering Tshuma, a £100,000-a-year senior IT manager who drives a BMW, had stood next to his estranged wife at their daughter's sports day hours before allegedly killing her and their childrenTshuma had told friends he did not want a divorce as he could not live without Zandile and their children (Pictured: Police at the family home on Wednesday)'It's absolutely heartbreaking what's happened and we are all devastated. Zandile was looking forward to the future and we'll all miss her terribly.'One Zimbabwean who claimed to be a friend of the IT expert wrote on social media: 'He was going through a divorce [I] told him to let her go but he couldn't.'In a tribute to Zandile and her daughters, a family member said: 'The Khumalo family is deeply saddened to confirm the passing of our beloved Zandile (Nothabo) Khumalo and her two children.'During this time of unimaginable loss, we wish to express our heartfelt gratitude to everyone who has reached out with prayers, messages of comfort, and support. Your kindness and compassion have brought great strength to our family.'As the circumstances surrounding their passing remain the subject of an official investigation, we are unable to comment further at this stage. We are also awaiting guidance from the relevant authorities before confirming funeral and memorial arrangements.'We respectfully ask for patience and understanding as the necessary processes are completed. An official update will be shared as soon as further information can be released.'We kindly request that the media and members of the public respect our family's privacy during this profoundly difficult time and refrain from sharing or circulating unverified information or speculation.'The Khumalo family sincerely appreciates the continued love, prayers, and support shown by family, friends, and the wider community.'Mrs Gemma Gibson, Headmistress of Bedford Girls' School said of 15-year-old Natalie: 'Natalie was a bright and accomplished Year 10 student who was dearly loved by everyone at Bedford Girls' School. She was a talented dancer, musician and keen sportswoman. 'She was fun loving, full of life and had a positive impact on everyone she came into contact with; she will be remembered with warmth and affection. 'Her tragic death, together with that of her loving mother and younger sister, who were also well known to many of us, is a hugely devastating shock to all at Bedford Girls' School and the wider Harpur Trust group of schools. 'Our thoughts and prayers are with Natalie's wider family, friends and all of those impacted by this terrible news.'Headteacher Jo Webster, of Pilgrims Pre Prep School, added of Nala: 'Nala was a much-loved member of our school community who brought joy to those around her every day. Many of our staff had known her since she was seven months old and had the privilege of watching her grow. 'Known for her inquisitive and bubbly nature, positivity and wonderful sense of humour, she was a little ray of sunshine. Whether wearing one of her favourite colourful hair accessories, making those around her laugh or taking centre stage in our Pre-School Nativity, Nala brought warmth and happiness wherever she went. 'She had an extraordinary impact on our community and will be remembered with enormous love and affection. Our thoughts and deepest condolences are with Nala's family, friends and everyone affected by this heart-breaking loss.'Detective Inspector Lee Martin, Bedfordshire Police senior investigating officer, said: 'We have been carrying out numerous lines of enquiry as part of this fast-paced, complex investigation.'We know that Mark Tshuma left the country on Saturday and is now believed to be in Zimbabwe.'We are urgently working to find and apprehend him, and would appeal to him directly to hand himself in.'Addressing himself to Tshuma directly, he went on: 'Mark, unthinkable harm has been caused to those around you, and this has left your relatives and friends utterly devastated.'Criminal investigation knows no borders. We are actively working with national and international agencies to pursue every available line of enquiry to track you down.'Please do the right thing, come forward and hand yourself in to local authorities.'Zandile was a high achieving director specialising in financial crime, fraud investigations and anti-money laundering.She previously worked in global banking and consulting for companies including Barclays and KPMG and was vice chair of the Female Fraud Forum.The mother-of-two attended Midlands State University in Gweru, Zimbabwe, and later worked in Tanzania before the couple moved to Bedford in 2011.Tshuma studied Management Information Systems at Solusi University in Zimbabwe before completing his Bachelor of Sciences degree in Plymouth.He later studied for a diploma in Business Systems Analysis and Design at City St George's, University of London.Tshuma describes himself as a 'results oriented and energetic IT leader'.