The father of a Warwickshire English language teacher brutally murdered in Japan six months ago made an emotional appeal today for help in bringing her killer to justice.

Bill Hawker, of Brandon, near Coventry, handed leaflets to passengers flying to Tokyo from Heathrow Airport’s Terminal 3, urging them to look out for Tatsuya Ichihashi, the only suspect in the case.

His daughter, Lindsay, 22, was found bound with gardening tape in an earth-filled bath on the balcony of Ichihashi’s flat in Ichikawa, east of Tokyo, in March.

The young woman had been subjected to a sadistic attack, possibly lasting as long as 36 hours, before being strangled. Unemployed Ichihashi has remained on the run since fleeing when police arrived at his apartment.

Wearing a T-shirt with the suspect’s image below the word "Murderer", Mr Hawker spoke of his family’s tireless campaign to keep the case in the spotlight. He said: "My daughter’s murderer is still out there. Who knows, he could be planning his next victim.

"But as a family we have pulled together. I’ve got two other daughters, who I’m very proud of. As a family we want justice for Lindsay, which any father, any mother and any sisters would want.

"We’re not going to let this ruin the rest of our lives - but we’re certainly not going to give in in looking for justice."

Mr Hawker’s voice broke as he recalled waving his daughter off at the same terminal nearly a year ago as she set off for her adventure in Japan.

"It’s very difficult indeed. Twelve months ago I was so proud..." he said. "My beautiful daughter’s not coming back, and six months is a very hard day for us."

He praised the "very positive" attitude of the Japanese travellers to whom he, his sister, Sue Moynihan, and Miss Hawker’s best friend, Laura Thompson, handed the leaflets.

Mr Hawker was reluctant to criticise the Japanese authorities, but he said the flow of information from police had dried up somewhat recently.

The weekly updates the family receives from investigators have become "very repetitive", with officers again and again saying they are searching amusement arcades, internet cafes, gay bars and parks for Ichihashi, he said.

He added: "I’m sure if they gave us more information we would feel more confident in their ability to capture Ichihashi.

"I’m sure they’re doing far more than they’re telling us, but the lack of information makes us despair that they perhaps could be doing more."

Mr Hawker is also due to receive a briefing from the Chief Constable of Warwickshire Police, who spent a day in the police incident room devoted to the case while visiting Japan recently.

A key clue could be a missing memory card for Miss Hawker’s camera, her father revealed today.

He said: "Everywhere she went in Tokyo she took pictures, and I’m afraid that her camera has been discovered, but the photo card memory has never been discovered."

Last month, Mr Hawker, said Ichihashi may have drugged his daughter in a coffee shop before luring her back to his flat.

Today, he spoke of his uneasy feeling on watching CCTV footage of his daughter with the suspect at the shop.

He said: "I have the awful images of the pair of them getting out of the taxi, and she seems to follow him, not looking herself."

The leaflets handed out today carry a picture of Ichihashi and messages in both English and Japanese.

The English version states: "Lindsay was a beautiful girl who didn’t deserve to die - she had her whole life ahead of her and her family now urge you to help them get justice for Lindsay.

"When you arrive in Japan please remember the suspect’s face and if you see him or see anything suspicious please report it to the police in Japan."

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