UK government officials say an appeal by Home Secretary David Blunkett will help to trace the whereabouts of a seven-year-old boy who was kidnapped from his mother's custody in Sheffield and is believed to be staying with family friends or relatives somewhere in Jammu and Kashmir.

Blunkett, who is visiting India, made a weekend appeal for information about Nabeel Khan, who was snatched away by his father Iqbal during a routine access visit to his divorced wife's home last August and then taken on a false passport to Saudi Arabia.

Nabeel's frantic mother Tahseen Kauser was able to track him down through the British embassy in Riyadh, but Iqbal escaped by returning to India and going into hiding.

After six months with no word from her son, Tahseen was last night desperate for news.

"Nabeel is the first thing I think of in the morning and the last thing I think of at night. All day I wonder where he is and what he is doing," she says.

"I don't even know if my son is safe. I think his father has told him that his mother doesn't want him and has refused to come and see him.

"Nothing could be more wrong. My whole family is devastated. I can hardly sleep at night for worrying about my little boy.

"He was born in Sheffield and only really speaks English. He has only ever been away from the city once and he was so pleased to get back that he was hugging and kissing the signs at the train station.

"His whole life is in Sheffield, his friends, his school everything. He has just been torn away from everything he knows. I don't know how his father can be so cruel."

Nabeel, a football-mad youngster, is asthmatic and needs regular medication.

Iqbal, 42, was able to abduct his son by tricking the Passport Office into issuing a new passport after claiming the original had been lost.

A lecturer in civil engineering at Nottingham University, he had earlier signed papers pledging that he would never remove Nabeel from his mother or try and take him out of the country.

His former wife knew nothing about the second passport until he used it to sneak his son out of Britain.

Officials from the British embassy tracked them to Saudi Arabia and made an appointment for Iqbal to bring his son into the consul.

Later Khan took flight to India where his former wife is convinced his family is shielding him.

"They have said they don't know where he is, but I do not believe them," says the 43-year-old lady.

As diplomatic efforts are on to trace Nabeel in India, Tahseen believes the personal appeal by the home secretary is her best chance yet to be reunited with her son.

"There are so many ties between India and Britain that I am sure an appeal by the British home secretary will do some good," she said in a statement released through the UK media.

"This is the biggest step forward since he was taken from Saudi Arabia."

Blunkett has also taken the opportunity of his India trip to appeal for help in finding Maninder Pal Singh Kohli, the prime suspect in the murder of Southampton woman student Hannah Foster.

His intervention has already led to the promise to release North Yorkshire arms dealer Peter Bleach after a decade in jail.

Now UK officials hope Blunkett will help raise the profile of the hunt for Nabeel, who is thought to be somewhere in Jammu and Kashmir.

In London Denise Carter, director of the charity Reunite, the international child abduction centre, says help from high profile politicians can make a world of difference.

She says, "This has been a nightmare for Tahseen since last August and although six months is a not a long time in the grand scale of child abduction, every day will feel like an eternity to a mother whose child has been taken away."

Although India has not has not signed any international conventions dealing with children abducted by a parent, Carter said, "We are very pleased that David Blunkett has agreed to raise this case while in India.

"Hopefully it will prompt the Indian authorities to act and it will pave the way for further negotiations in dealing with children who are in India because they have been abducted by a parent."