Relatives of a teenager who has been missing for seven weeks believe she may have been kidnapped.

Janet Brown, the grandmother of 19-year-old Cheryl Harris said: "It is so out of character that she has not contacted us.

"We are suspicious something has happened. She may be being held against her will."

Miss Harris has been missing from her Brighton home since mid-September.

She took her passport and filled bin bags with clothes before leaving her house in Sandhurst Avenue, Woodingdean, where she lives with her mother and younger sister.

Police have checked airlines and believe she has not left the country.

Information suggests she may be living in a squat in Bournemouth and Dorset Police are helping with the search.

Miss Harris's family said they did not believe police had taken the case seriously enough but last night Detective Inspector Bill Warner said: "A thorough investigation is under way.

"Cheryl is 19 and free to go where she wants but we are concerned for her safety.

"There is no evidence anything untoward has happened but we are taking the case seriously. We appeal to anyone with information to come forward."

Miss Harris, a former shop assistant, now unemployed, has never gone missing before and her family has no idea why she has left.

She is not drawing benefits and police do not know how she is getting money to live on.

Miss Harris's mother Sarah said her daughter was happy at home with her sister Kirsty, 13.

She said: "She has left her two cats and my horse which she loves.

"Kirsty is missing her big sister very much and there were no rows at home or problems with boyfriends.

"We want to know she is safe and well. Please Cheryl, contact someone."

Mrs Brown, who lives in Brighton, said she and her granddaughter were close.

She said: "She loves her mobile phone and is always texting.

"Her mobile is now switched off and no one is getting through or receiving any messages. It is just not right. Something has happened."

Miss Harris is 5ft 1in and slim. Anyone with information about her whereabouts should contact Brighton and Hove CID on 0845 6070999.