Detectives searching for Ben Needham – who went missing as a toddler 24 years ago – have said that an appeal on Greek TV has generated fresh leads.

Ben, from Sheffield, disappeared in 1991 when he was 21 months old during a family holiday on the island of Kos.

The Greek TV programme Light at the End of the Tunnel regularly reaches around 50% of the Greek TV audience. Kerry Needham, Ben's mother, appeared on the programme yesterday to make a fresh appeal for information about her son.

Since the broadcast at least 20 phone calls and emails have been received. In addition, a photograph has been sent in, which detectives are now examining. Detective Inspector John Cousins of the South Yorkshire police said of the ongoing investigation into Ben's disappearance: "We have put a dedicated team together and all of us are intent on finding the answer as to where he has been and what has happened to him."

His mother has always maintained her son remains alive. If so, he would now be 25.

"It is just a feeling I have inside myself," she said. "It feels like he is saying 'come on I am here, come and get me'. I believe he's out there, I don't think it's going to be long, we are going to get somewhere. I am hopeful, anyway. I want him to know, as his mum, I love him as much today as the day he was born. I will never, never stop looking for him."

Ben's grandmother Christine and his sister Leighanna also took part in the programme.

Ben vanished on 24 July, 1991. He had been taken to Kos with his mother and his grandparents, who were renovating a farmhouse in the village of Iraklise on the island.

Earlier this year, South Yorkshire Police were given more than £700,000 from the Home Office to fund continuing inquiries to find Ben. In conjunction with yesterday's broadcast, Crimestoppers have offered a new £10,000 reward and urged member of the public to share the #BenNeedham hashtag.