An Garda Síochána has marked the 40th anniversary of the disappearance of Philip Cairns with a fresh appeal for information. Philip vanished on the afternoon of 23 October 1986 while walking between his home and his school, Coláiste Éanna, in Rathfarnham, Dublin 16. Despite an active and ongoing investigation, he has never been found.

The 13-year-old had left Coláiste Éanna at 12.50pm to go home to Ballyroan Road. At around 1.30pm, he picked up his schoolbag and set out to return to school, but he did not arrive and his family never saw him again.

Six days later, Philip's schoolbag was discovered in a laneway near the school linking Ann Devlin Road and Ann Devlin Drive. Some of his books were missing from the bag.

Philip was 5'2" tall with short black hair. When last seen, he was wearing his Coláiste Éanna uniform: a grey jacket with black shoulder corners, grey school trousers, a grey shirt and a school pullover.

Marking the anniversary, Gardaí have renewed their public appeal for any information that could progress the case. Over the four decades since Philip disappeared, investigators have pursued more than 1,600 lines of enquiry. The inquiry team continues to receive contact and information from members of the public on a regular basis and remains in ongoing contact with the Cairns family.

Significant media coverage in recent weeks and months has brought the case back to the forefront of public discussion and has generated new pieces of information.

In line with standard practice, any recent information provided is being examined and assessed to determine its evidential value.

Gardaí are particularly keen to hear from anyone who, prompted by recent media attention, is now in a position to speak with investigators; anyone who has information about Philip's disappearance or his schoolbag but has not yet come forward; and those who were too young at the time to assist but may now be able to provide relevant details. With the passage of time and changing circumstances, such individuals may now be able to help and provide answers for Philip's family.

An Garda Síochána assures anyone who comes forward that they will be treated sensitively and with discretion by investigating Gardaí. Even the smallest detail, no matter how insignificant it may seem, could prove important.

Anyone with information is asked to contact Rathfarnham Garda Station on 01 666 6500, the Garda Confidential Line on 1800 666 111, or any Garda station.