Parents still looking for answers after their 15-year-old son went missing 23 years ago are to appear in a BBC documentary.

Lee Boxell disappeared on September 10, 1988, after leaving his home in Cheam, Surrey, to meet up with a friend in Sutton High Street.

Before they left each other, Lee told his friend he might go to Selhurst Park to watch a football match.

His family have never seen him again.

His disappearance, and the anguish of his parents, Peter and Christine Boxell, was one of the subjects of a 1995 book The Missing.

Author Andrew O’Hagan rewrote his book as a play, which was performed for the first time in September.

BBC Scotland is now making a documentary where Mr O’Hagan revisits the people he interviewed for the book.

The programme will also be interspersed with scenes from the play.

Mr Boxell said: “It is always hard going over it all again. It brings back a lot of our memories about Lee.

“Although it is 23 years ago it still feels like it was yesterday.”

Several weeks ago a film crew visited the Boxell’s home and Sutton High Street with Mr O’Hagan.

Mr and Mrs Boxell have so far chosen not to watch the play because they thought it would bring back too many painful memories.

After 23 years, Mrs Boxell is still hopeful Lee, who would now be 38-years-old, will one day walk through the door again.

She said: “I know it is increasingly unlikely because of the time that has passed, but I have to keep up hope.”

She has kept her son’s room the same – his Cheam High School uniform still hangs in the wardrobe.

Lee’s family have become involved with the charity Missing People and have been invited to meet its patron the Duchess of Gloucester at a Christmas concert in December.

The documentary about Lee’s disappearance is due to be screened in December.