The parents of a brilliant young artist who hanged herself after taking a controversial drug have backed plans to sue its manufacturer.

New York's top prosecutor has filed fraud charges against Crawley-based GlaxoSmithKline (GSK) claiming the company hid evidence that showed the anti-depressant Seroxat made children and teenagers suicidal.

Sharise Gatchell, 18, from Newhaven, hanged herself last May after taking the drug.

She had been prescribed it without the knowledge of her parents, who found her body when they returned home after a weekend away.

Her father Alfred and mother Stephanie allege the drug led to her death.

Mrs Gatchell said yesterday: "I welcome this. What has happened is a highlight in our campaign against Seroxat. We are making progress."

Attorney General Eliot Spitzer claims the company kept secret from American doctors four studies that showed Seroxat was no more effective than a placebo.

His lawsuit also alleges that five studies carried out by the company between 1998 and 2002 showed an increase in suicidal tendencies in young patients in some trials.

An internal GSK document from 1998 quoted in the lawsuit warns the firm planned to "effectively manage the dissemination of these data in order to minimise any potential negative impact."

South African-born Sharise, an art foundation student at City College, Brighton, was prescribed Seroxat to help her battle shyness and depression.

But her condition deepened and she experienced dramatic mood swings.

She agreed with her parents to come off the drug but was given a new prescription without their knowledge shortly before her death.

Mrs Gatchell said: "I don't really know what to do next but I won't rest until there is justice.

"I'm feeling raw - it is still incredibly difficult. Every single day since we lost her has been a nightmare."

Doctors in Britain are banned from treating children with Seroxat, one of a class of anti-depressants known as selective serotonin re-uptake inhibitors.

An estimated 17 million people worldwide have taken the drug since it was first licensed in 1990, attracted by promises of defeating depression while suffering fewer side effects than any other treatment.

But the Medicines and Healthcare Regulatory Agency published research last year showing depressed under-18s were three times more likely to self-harm or attempt suicide on Seroxat than when taking a placebo.

A spokesman for GSK said the company had "acted responsibly" with its clinical studies, making the results known in medical journals.