A person who has undergone a sex change is fighting a legal battle for the right to have her previous identity as a man officially "forgotten".

The case of C, who cannot be identified for legal reasons, is being seen as a landmark case concerning the rights of transgender persons across the UK.

The 44-year-old, from the Greater London area, is challenging the legality of the Government's retention and use of personal information which reveals she was once male.

Her case centres on the data held on her by the Department for Work and Pensions (DWP) as a long-term unemployed person in receipt of jobseeker's allowance.

She says, because details of her transgender status have become known to DWP personnel, she has experienced "intrusive and humiliating interactions" on visits to her local Jobcentre Plus on a fortnightly basis.

Claire McCann, representing C, told a judge at London's High Court: "She says her previous gender identity as male should be forgotten, except where it is strictly necessary.

"The right to be treated as a woman and not as transgender is important and deserving respect."

Ms McCann referred to a ruling won by a Spanish man in the European Union Court of Justice against Google that he had a "right to be forgotten" and "irrelevant" and outdated data about him held by the search engine should be erased at his request.

Ms McCann said of C's case: "This case far more acutely concerns the right to be forgotten."

C considered her gender reassignment "an intensely private matter" and "wholly irrelevant" to her attempts to find work.

Ms McCann said C had obtained a full gender recognition certificate (GRC) under the 2004 Gender Recognition Act after many years of struggle involving "numerous procedures and at great physical and emotional cost".

Now that transgender persons, in the UK at least, had full recognition in law it was "fundamental that this recognition should be fully realised, practically and effectively".

But the DWP was retaining her gender change data on its Customer Information System (CIS) and Jobseekers' Allowance Payment System, including her previous male name.

The DWP automatically processed the records of transgender customers as "special customer records" and applied a "sensitive account" marker to keep details confidential, but this failed to give sufficient protection, argued Ms McCann.

C's details had become known to DWP staff who lived within her locality.

At the same time the extra layers of security were leading to her receiving a poor service, including late payments of benefits.

Ms McCann argued the intrusive, unnecessary and indefinite retention of C's details by the DWP was in breach of her human rights, as well as data protection and anti-discrimination legislation.

Lawyers for the DWP argue its policies are not discriminatory or intrusive but carefully balance the need to give effect to C's legal rights while the department carries out its functions.

They also argue Parliament expressly contemplated the data would be held by social security and pension systems, and there was no requirement to "rewrite history" and delete information that recorded a person's previously held gender.